ISSN 1393-614X Minerva - An Internet Journal of Philosophy Vol. 9 2005.


Descartes: Libertarianist, Necessitarianist, Actualist?

Timo Kajamies



According to necessitarianism, all truths are logically necessary, and the modal doctrine of a necessitarian philosopher is in a sharp contrast with something that seems manifest—the view that there are contingent truths. At least on the face of it, then, necessitarianism is highly implausible. René Descartes is usually not regarded as a necessitarian philosopher, but some of his philosophical views raise the worry as to whether he is committed to the necessity of all truths. This paper is an appraisal of this worry.



1. Setting the Stage

According to necessitarianism, all truths are logically necessary. A necessitarian philosopher does not allow logically contingent truths, and her modal doctrine is therefore in a sharp contrast with our ordinary modal beliefs. I have quite a firm belief that Descartes is not among partisans of necessitarianism, but it appears that some essential passages in the Cartesian corpus provide room for being worried as to whether this belief really holds water. This paper is an attempt to raise and assess that worry.


The question whether one is committed to necessitarianism is connected with the question whether one’s ontology contains unactualized possibilities. A necessitarian philosopher does not have any use for such things as possible but nonactual worlds, beings, states of affairs, and what not. If there are no contingent truths, the approval of nonactual worlds would have no explanatory value and would only amount to needless ontological extravagance. A necessitarian, familiar with Ockham’s razor, should therefore renounce nonactual entities. At first sight, nothing in Descartes’s modal metaphysics suggests that he endorses necessitarianism, for he seems to have no reluctance to posit nonactual beings. As we shall see, there appears to be a lot of theoretical use for unactualized possibilities in his philosophy, which is hard to combine with the view that his philosophy contains a necessitarian strand. However, it has been recently argued that Descartes is an actualist, i.e., a philosopher whose ontology does not contain nonactual entities. This, I believe, raises the the question of necessitarianism in the discussion of Descartes’s modal views. After all, according to a very straightforward account of counterfactual possibility, the existence of possible but nonactual entities—contingently nonactual worlds for instance—make some propositions counterfactually possible. This analysis is not available to an actualist, and she should provide a different account as to how her ontology is supposed to allow there being contingently true propositions. So, if Descartes were an actualist, he should be able to explain, without committing himself to nonactual entities, how there can be room for contingency in his philosophical thought, or else his system can be seen as leading to the view that every proposition is either necessarily true or necessarily false.


Descartes’s views notwithstanding, necessitarianism is, prima facie at least, highly implausible. Why would one ever claim that all truths are necessary? We seem to have such a strong intuition that some things happen without being inevitable, and vice versa, that there are things which could happen but which in fact do not. What motives could there be behind the view that an intuition of this sort is misguided and that all truths are necessary? At least one of the motives can arguably be found in rationalist maxims of explanation. Rationalism, seen from this angle, is understood as a doctrine including the view that there is an answer to every why-question (Bennett 1996, 61), be the discovery of that answer as hard and challenging a task as it may. Leibniz (AG, 209; AG, 321) famously holds that nothing happens without a sufficient reason, and that everyone who knows enough should be able to explain why a given event occurred rather than something else. In a somewhat similar vein, Spinoza (E1p11d2) believes that there is a reason for the existence or non-existence of each thing. Both Leibniz and Spinoza seem to hold that there is nothing ultimately without a sufficient reason, and therefore both seem to be proponents of explanatory rationalism.


If Spinoza is seen as an explanatory rationalist, he should hold that every question “Why did event e occur?” has an answer. According to Spinoza, particular things and events, or finite modes as he says, are caused by other particulars or finite modes. There is, Spinoza (E1p28 and E1p28d) holds, an infinite causal chain of finite modes, in which every finite mode is causally determined, by natural laws, from antecedent conditions. Accordingly, the occurrence of any event can, in Spinoza’s philosophy, be explained by appeal to its antecedent conditions, together with natural laws which link causes with effects. However, causal determinism is compatible with the metaphysical contingency of the total infinite causal series (e.g. Carriero 1991, 55; see also Garrett 1991, 192), so the infinite causal ancestry of an event does not amount to an ultimate explanation of the event, unless there is an explanation as to why the causal series occurred rather than some other causal series. For an explanatory rationalist, the occurrence of the entire causal chain cannot be a mere brute contingent fact, and she must either explain the occurrence of the chain through something external to that chain, or else she must deny that the chain is contingent. Spinoza takes the latter course and arrives at the doctrine of necessitarianism, according to which there is nothing contingent in the universe; everything is absolutely necessary right down to the smallest detail.[1] Indeed, Spinoza writes that “In nature there is nothing contingent, but all things have been determined from the necessity of the divine nature to exist and produce an effect in a certain way” (E1p29), and “Things could have been produced by God in no other way, and in no other order than they have been produced” (E1p33). Spinoza’s aspiration for explanatory rationalism seems to end up in the necessitarian thesis that there are no unactualized possibilities, or, to use contemporary terms, in the thesis that there is only one world, no possible worlds besides the actual one (e.g. Sleigh, Chappell & Della Rocca 1998, 1227; Garrett 1991, 191-92).


In Descartes’s philosophy, the universal explanatory maxim cannot motivate necessitarian thinking, because Descartes is, in fact, committed to the denial of explanatory rationalism. This commitment emerges from his curious views on the causal origin of modalities. Notoriously, Descartes believes that necessary truths, or eternal truths as they were called at that time, are freely created by God. In April 1630, in one of his letters to father Mersenne (CSMK III, 25, AT I, 151-53), Descartes first expresses this puzzling voluntarist view as follows:


The mathematical truths which you call eternal have been laid down by God and depend on him entirely no less than the rest of his creatures. Indeed to say that these truths are independent of God is to talk of him as if he were Jupiter or Saturn and to subject him to the Styx and the Fates. Please do not hesitate to assert and proclaim everywhere that it is God who has laid down these laws in nature just as a king lays down laws in his kingdom.


Descartes’s voluntarism includes the view that eternal truths are not known by God because of their truth, but vice versa, they are true because God knows them. This view is in a sharp contrast with the position of scholastic intellectualists (see Osler 1995, 147), such as that of Francisco Suárez, who writes in his Disputationes Metaphysicae, XXXI that the eternal truths “are not true because they are known by God, rather they are known because they are true, otherwise no reason could be given why God necessarily knows that they are true, for if their truth proceeded from God himself, that would happen by means of God’s will, so it would not proceed necessarily but voluntarily” (quoted in Curley 1984, 585-86).


Descartes’s view sounds very extraordinary, and one is immediately led to wonder what the free creation of eternal truths could mean and what could be the rationale for this view (for theologico-philosophical background of Descartes’s voluntarism, see Kajamies 2004). Following Leibniz (e.g. AG, 220) one might, for instance, suggest that creation amounts to the actualization of pre-existing possibilities, and try to understand Descartes’s view of the causal origin of modalities through a Leibnitian model. According to this interpretation, the establishment of eternal truths would, so to speak, amount to a Divine choice, performed within a set of pre-existing alternative possibilities. However, this cannot be the right interpretation of Descartes’s thought, because, as a true modal voluntarist, he should hold that the supposed pre-existing possibilities themselves be created; no universe of possibilities could pre-exist God’s creation. More generally, there could not be any kind of standard, purpose, goal or model guiding or restricting God’s creative acts prior to those acts themselves. As Descartes (Replies to Sixth Objections, CSM II, 291, AT VII, 431; see also Letter to Mesland, CSMK III, 235, AT IV, 118) says, God is absolutely indifferent with respect to everything which has happened or will ever happen, “free to make it not true that all the radii of the circle are equal—just as free as he was not to create the world” (Letter to Mersenne, CSMK III, 25, AT I, 152), which shows that Descartes’s God has no reason behind his creative acts. For Descartes, nothing can necessitate, or even incline without necessitating, God to perform any given creative act. Indeed, as Suárez (op. cit.) seems to worry, the question “Why God willed and decreed as he did?” ultimately remains unanswerable in genuine modal voluntarism, and therefore Descartes should not be seen as an explanatory rationalist.[2]


Because nothing explains God’s actions in modal voluntarism, it is certainly not easy to avoid the view that eternal truths, according to a voluntarist, hold good because of an arbitrary caprice or whim of God (see Frankfurt 1977, 54). This sort of arbitrariness later troubles Leibniz (Second Letter to Clarke, AG, 323), who claims that “the bare production of everything would indeed show the power of God, but it would not sufficiently show his wisdom.” According to Leibniz, “the efficient cause of things is intelligent” (Letter to Philipp, L, 273), having a reason behind his actions. Leibniz’s God is “striving for the good” (ibid.), and therefore his actions can be explained by appeal to what is best (Letter to Magnus Wedderkopf, L, 146). However, on Descartes’s view, according to Leibniz’s (ibid.) interpretation of voluntarism, goodness is subordinate to God’s free will, and therefore the will of Descartes’s God “would be a certain absolute decree, without any reason” (ibid). I believe Leibniz rightly points out that there is no reason behind God’s acts of will in Descartes’s voluntarism.


Yet, even though explanatory rationalism is not there to motivate necessitarianism in Descartes’s philosophy, some of his writings give grounds for posing the question, at any rate, whether he is committed to necessitarian thinking. In particular, his views on the ethics of belief, including his conception of human freedom, set the stage for the worries that he might be committed to necessitarianism. Generating these worries will be one of the two main goals I have in this paper. The other aim will be to discuss the interpretation according to which Descartes does not admit possibilia into his ontology and to work out the consequences of this interpretation with regard to the problem of necessitarianism.


2. Truth Rule, Compelled Assent, and Necessitarianism

Cartesian Ethics of Belief

In the Meditations (CSM II, 12, AT VII, 17), Descartes proposes that once in his life he has to pull down the system of beliefs he has been building since childhood and start from the beginning, in order to find something epistemically stable and lasting. In his pursuit of a new stable system of knowledge Descartes decides to hold on to nothing else than what is beyond any doubt. “Reason now leads me to think that I should hold back my assent from opinions which are not completely certain and indubitable”, he writes in the First Meditation (CSM II, 12, AT VII, 18).


Descartes’s doubt comes forth in the Meditations in successive waves, starting from sensory perceptions and extending all the way to the attempt to doubt basic mathematical propositions. He states that the only reason for doubting the simple propositions of arithmetic and geometry is the hypothesis that God somehow deceives him in these matters (CSM II, 25, AT VII, 36). After proving the existence of a veracious God, Descartes (CSM II, 43, AT VII, 62), however, believes that he is entitled to believe in the things he conceives with utmost clarity and distinctness:


If I restrain my will so that it extends to what the intellect clearly and distinctly reveals, and no further, then it is quite impossible for me to go wrong.


This brings out the core of Descartes’s conception of the ethics of belief. In Descartes’s deontological epistemology, fulfilment of one’s basic epistemic duty requires careful employment of one’s mental capabilities. In particular, the active operations of the mind are of a special importance. In Descartes’s philosophy of mind, mental operations fall into two fundamental and exhaustive classes—active operations of the will and passive operations of the intellect (e.g. Principles of Philosophy I.32, CSM I, 204, AT VIIIA, 17), and the way in which one actively uses one’s will is what makes one’s actions epistemically praiseworthy of blameworthy. One cannot be held responsible for wholly passive and involuntary operations. Automatons, for instance, cannot be praised or blamed for their operations, because, unlike human agents, they do not possess any aptitude for voluntary acts. Thus, the notion of responsibility, be it moral or epistemic, includes the notion of capacity for free action.[3] And freedom of the will, Descartes believes, is self-evident and one of our most fundamental innate notions. Our experience of freedom is so great, and our awareness of it so close, that nothing can be grasped more evidently (Principles of Philosophy I.41, CSM I, 205-6, AT VIIIA, 19-20).


For Descartes, the free actions suitable for epistemic appraisal are special kind of modes of will: acts of assent. According to Descartes, one can, at will, assent to the ideas presented by the faculty of intellect, and when one freely assents to something that is not clear and distinct, one freely runs the risk of error and can be blamed for an undutiful epistemic deed. Not all deliverances of our understanding ought to be believed, for the faculty of understanding sometimes delivers something obscure and confused, and if such an obscure and confused item is believed, negligence of epistemic duties takes place.[4] Descartes’s theory of error, therefore, is grounded in doxastic libertarianism, understood as a view according to which belief is explicable in terms of freedom of the agent.


The truth rule raises the question of the nature of clarity and distinctness, the feature whose presence entitles the epistemic agent to assent to the idea possessing it. One of the features Descartes often mentions when discussing clear and distinct ideas is indubitability. Again, his characterizations of indubitability sometimes have a markedly psychologistic tone, suggesting that the notion of indubitability comes very close to that of doxastic irresistibility. For example, in his letter to Regius Descartes (CSMK III, 147, AT III, 64) writes that “our mind is of such a nature that it cannot help but assenting to what it clearly and distinctly understands.” Another psychologistically toned expression can be found in Principles of Philosophy, where Descartes (CSM I, 207, AT VIIIA, 21) writes: ”the minds of all of us have been so moulded by nature that whenever we perceive something clearly, we spontaneously give our assent to it and are quite unable to doubt its truth.” It is not hard to find a passage of this sort in the Meditations either. In the Fifth Meditation, while discussing the most simple clear and distinct ideas, Descartes (CSM II, 45, AT VII, 65) writes that “the nature of my mind is such that I cannot but assent to these things, at least so long as I clearly perceive them.” Therefore, Descartes seems to hold that clear and distinct ideas, as a psychological matter of fact, compel assent. It is a disputed question whether psychological irresistibility can be used as a criterion of clarity and distinctness (for a psychologistic view, see Larmore 1984; Rubin 1977; Loeb 1995; for an opposing view, see Frankfurt 1968; Gewirth 1941 and 1970; and Doney 1955). However, provided that an idea is clear and distinct it is, for Descartes, psychologically irresistible.


Now, the role of will in Descartes’s ethics of belief was considered problematic already by Descartes’s contemporaries. In the Third Objections, Hobbes (CSM II, 135, AT VII, 192) expresses his criticism as follows:


Further, it is not only knowing something to be true that is independent of the will, but also believing it or giving assent to it. If something is proved by valid arguments, or is reported as credible, we believe it whether we want to or not. It is true that affirmation and denial, defending and refuting propositions, are acts of will; but it does not follow that our inner assent depends on the will. There is thus no valid demonstration of the subsequent conclusion, viz. ‘In this incorrect use of free will may be found the privation which constitutes the essence of error’.


As I understand Hobbes’ criticism, he argues, firstly, that because there are cases—such as perceiving some proposition p clearly and distinctly or perceiving the validity of an argument for p—in which we believe p whether we want to or not, it cannot be generally true that believing depends on the will. Doxastic libertarianism, according to Hobbes, cannot be universal, because believing a conclusion of a valid argument is involuntary. Secondly, he argues that because believing is not always free, Descartes has not demonstrated that error arises from incorrect use of will. This second argumentative step by Hobbes is not, as such, an argument against Descartes’s theory of error, but rather an attempt to prove that Descartes’s argumentation for his theory of error is not conclusive. To function as an argument against Descartes’s theory, Hobbes’ argument should be supplemented with a further argument either to the effect that believing in absence of clarity and distinctness is not voluntary, or, even more strongly, to the effect that absence of clarity and distinctness is always accompanied with suspense of judgment.


To me it seems that the former supplementary argument is easier to carry out than the latter. It is reasonable to ask what believing in absence of clarity and distinctness might mean, and Descartes’s theory seems to suggest that we can, so to speak, arbitrarily decide or choose to believe in things we do not perceive distinctly. Wilson (1978, 144ff) claims, and I am inclined to agree with her, that it is implausible to suppose that believing in absence of clarity and distinctness is nothing but an arbitrary decision of a wanton mind—it may even be phenomenologically impossible just to decide to believe or assent to something (Curley 1975, 177-78). The latter supplementary argument leads to the Spinozistic view that suspension of judgement is nothing but seeing that one’s perception is not clear and distinct. According to E2p49s, (the addition in square brackets is in the quoted text): “I reply by denying that we have a free power of suspending judgment. For when we say that someone suspends judgment, we are saying nothing but that he sees that he does not perceive the thing adequately. Suspension of judgment, therefore, is really a perception, not [an act of] free will.” It has been argued by Curley (1975, 177) that Spinoza was right in claiming, against Descartes, that suspending judgment is simply finding arguments pro and con to be inconclusive. According to Curley, absence of clarity and distinctness can lead to nothing else than suspension of judgment. However, I agree with Wilson (1978, 146) that it is much less obviously wrong to suppose that one can make a judgment in the absence of clarity and distinctness than to suppose that believing in absence of clarity and distinctness is nothing but an arbitrary decision. There seems, then, to be no straightforward way of making Hobbes’ argument conclusive against Descartes’s view that error depends on misuse of will.


Indifference and Spontaneity

For present purposes, the first stage of Hobbes’ argument is more relevant than the ways in which Hobbes’ argument could be supplemented. To be plausible, the first stage seems to include the implicit premise that nothing can be, so to speak, both forced and voluntary. According to Hobbes, seeing that an argument is valid forces an inner assent upon us, which contradicts the view that believing always is a free act of will. It is perfectly natural to raise this critical point against Descartes, for the combination of the view that clarity and distinctness compel assent, and the view that assent neverteheless is a free act of will, surely seems problematic. Furthermore, as Descartes’s doxastic advice is that one should assent to all and only those propositions which one clearly and distinctly understands, the irresistibility of clear and distinct ideas not only seems to make the use of free will in the pursuit of truth completely redundant, but it also seems to free the followers of Descartes’s epistemic advice from epistemic responsibility.


As far as I can see, the answer Descartes gives to Hobbes in the Third Replies is quite unsatisfactory as such, but what he writes elsewhere enables him to provide a more plausible response to the criticism that compelled assent cannot be an act of free will. In the Fourth Meditation, Descartes (CSM II, 40-41, AT VII, 57-60) draws an important distinction between two senses of freedom: freedom of spontaneity and freedom of indifference. Descartes (CSM II, 40, AT VII, 58) tells us he experiences freedom of indifference “when there is no reason pushing me in one direction rather than another”.[5] Supposing that believing is voluntary, this sense of freedom seems fairly unproblematic, for it is characteristic of freedom of indifference that nothing forces the will to one doxastic direction rather than another. It is entirely up to the will to make the doxastic choice. Nevertheless, we immediately see that freedom of indifference is not what is at stake when it comes to clear and distinct ideas. A compelled act of assent cannot be an act which manifests freedom of indifference. Freedom of spontaneity, however, seems quite well tailored to describe the case of compelled assent. When our will exhibits freedom of spontaneity, Descartes (Letter to Mesland, CSMK III, 234, AT IV, 117) says, it “follows so promptly the light of our understanding that there is no longer any indifference at all.” But while the amount of spontaneity is inversely proportional to the amount of indifference in this way (see also Fourth Meditation, CSM II, 41, AT VII, 59), we might ask whether the amount of spontaneity is similarly proportional to the amount of freedom. After all, freedom of spontaneity seems to include some sort of resignation of the will to some antecedent assent-compelling conditions. We should ask how spontaneity can be a genuine brand of freedom before we can accommodate ourselves to what Descartes (CSM II, 40, AT VII, 57) says in the Fourth Meditation:


The will simply consists in our ability to do or not do something (that is, to affirm or deny, to pursue or avoid); or rather, it consists simply in the fact that when the intellect puts something forward for affirmation or denial or for pursuit or avoidance, our inclinations are such that we do not feel we are determined by any external force.


In this passage Descartes discusses both indifference and spontaneity, and there is no doubt that he considers spontaneity as a genuine kind of liberty. What he says is that freedom of the will consists in indifference or, rather, in spontaneity. Anthony Kenny wonders what the force of ‘rather’ is in the passage just quoted. Does it perhaps mark second thoughts, so that Descartes withdraws the statement that freedom consists in indifference? Does he identify the two kinds of freedom? Kenny argues, I believe convincingly, that Descartes believes that freedom often involves indifference, but sometimes it consists only in spontaneity. (Kenny 1972, 18-19.) On this view, Descartes acknowledges both kinds of freedom as genuine. Nevetheless, Descartes (Fourth Meditation, CSM II, 41, AT VII, 59) holds that the freedom of our belief is at its greatest when our assent is spontaneous without any trace of indifference. So, questions remain as to how spontaneity can be a full-fledged type of freedom.[6]


One sense in which spontaneous acts of assent can be held to be free lurks right under the surface of a much quoted passage in the Fifth Meditation (CSM II, 48, AT VII, 69):


Admittedly my nature is such that so long as I perceive something very clearly and distinctly I cannot but believe it to be true. But my nature is also such that I cannot fix my mental vision continually on the same thing, so as to keep perceiving it clearly; and often the memory of a previously made judgement may come back, when I am no longer attending to the arguments which led me to make it. And so other arguments can now occur to me which might easily undermine my opinion, if I were unaware of God; and I should thus never have true and certain knowledge about anything, but only shifting and changeable opinions.


Here Descartes says, firstly, that he cannot but assent to what his intellect clearly and distinctly presents, and, secondly, that later on when clarity and distinctness are no longer present in an idea he can fall into doubt about the truth of the idea, and his assent is no longer compelled. The idea, in so far as it is not clear and distinct any longer, is no longer a reason inevitably pushing his will, and other reasons may occur that incline his will to other directions. In other words, the amount of indifference easily increases when a once clear and distinct idea no longer is clear and distinct. The reason for the loss of clarity and distinctness is, we are told, that one cannot continuously fix one’s attention to the same thing. Diverting one’s attention from an irresistible clear and distinct idea leads, through the loss of clarity and distinctness, to the ability to withhold assent from the idea, or even to the ability to make a contrary judgement (Letter to Mesland, CSMK III, 234, AT IV, 116-17). Descartes’s letter to Mesland (ibid.) reveals that we can control our attention so that the inclinations of our will become more spontaneous: “it is a good action to pay attention and thus to ensure that our will follows so promptly the light of our understanding that there is no longer any indifference at all.” On my view, Descartes believes that we can freely choose whether we pay attention to clear and distinct ideas or not, or, in deciding whether we pursue clarity and distinctness or not. Peter Schouls (1989, 103) has put this point quite elegantly by saying that “the exercise of liberty of indifference will create the conditions for the experience of liberty of spontaneity.” Therefore, freedom of spontaneity really is a genuine brand of freedom at least in the sense that we can freely commit ourselves to be led by clarity and distinctness. The conclusion I set forth here is in agreement with Alanen’s (1999, 111) view that, not being programmed like automata, we can voluntarily shift our attention away from a clear and distinct idea and thus avoid assenting to it. Even if doxastic libertarianism did not apply after we have exercised the faculty of clear and distinct perception, it applies a step back, so to speak.


In addition of our being free to commit ourselves to pursue clarity and distinctness, there is another sense in which agents experiencing spontaneity can be held to be free. While we are spontaneous, “our inclinations are such that we do not feel we are determined by any external force”, says Descartes (CSM II, 40, AT VII, 57). The notion of external force is of great importance here. The lack of external determining forces in spontaneous assent means that the mind works autonomously, in a self-legislative way. Mind, the agent which exercises the power of willing when a spontaneous assent occurs, produces its volitions by itself. There is no agent external to the mind participating in the production of these volitions. As Descartes (Letter to Mesland, CSMK III, 234, AT IV, 116) writes, freedom should not be viewed as “indifference but rather as a real and positive power to determine oneself”, which means that the mind can be seen as an autonomous, free agent. Freedom as the autonomy of mind is a theme that extends all through the Meditations, and is of a special importance in Descartes’s epistemology. The Meditations can be seen as a guide of liberating one’s mind of bodily impulses and of ideas whose production is, at least partly, due to the senses. When the mind has turned away from the senses in the sense of abandoning the Scholastic view that concepts are abstracted from experiences (Carriero 1990, part I), and taken up the contemplation of innate ideas instead, it can, by the use of reason, build a stable system of knowledge instead of a shaky system of mere opinions. An autonomous mind, one that has chosen to pursue clarity and distinctness, assumes its epistemic responsibilities in the best possible way.


Even if Descartes can argue that spontaneous assent exhibits the autonomy of mind, a problem seems to remain in Descartes’s account of spontaneity. An autonomous mind is admittedly an agent which determines itself to action, but the way in which this determination works while the mind is spontaneous leaves, in a sense, very little for the will to do. In case of spontaneous assent, it seems, the will plays no significant role in the transition from a clear and distinct idea to a belief. We can direct our attention at will so as to engage ourselves in the pursuit of clarity and distinctness, but do we need any will to transform a clear and distinct idea into a belief? Bernard Williams (1978, 183; see also Wilson 1978, 141ff) brought this question up, and rigthly so, in his book on Descartes by saying that “if in this sense I clearly understand a proposition—that is to say, I can see it is true—there is nothing else I have to do in order to believe it: I already believe it. The will has nothing to do which the understanding has not already done.” We are, in an important sense, brought back to Hobbes’ criticism, according to which we believe the outcomes of valid arguments whether we want to or not. In Descartes’s theory of spontaneous assent, the gap between understanding a proposition distinctly and believing it as true seems not large enough for the will to have any work in the production of the belief. In case of clear and distinct perception, understanding hardly falls short of believing.


On this view, Descartes’s account of affirming clear and distinct ideas sounds quite Spinozistic. In E2p49 Spinoza writes that “In the Mind there is no volition, or affirmation and negation, except that which the idea involves insofar as it is an idea.” Spinoza emphasizes that it is wrong to understand the notion of judgement as including an act of will which is directed towards an idea distinct from the volition. It seems that Descartes’s view of clear and distinct ideas commits him to a position not far from Spinoza’s account, according to which ideas are inherently judgmental. An important difference, however, remains between Spinoza and Descartes here: whereas for Spinoza will and intellect are identical (E2p49c) and hence all ideas, including the so-called inadequate ideas, are inherently judgmental, Descartes certainly does not accept, nor is committed to accept, the view that obscure and confused ideas do not fall short of affirmation or denial. But as far as clear and distinct ideas are concerned, Descartes is committed to a view which closely resembles Spinoza’s theory of judgement.


The Problem of Necessitarianism

The unity of understanding and believing in cases of clear and distinct perception brings us, finally, to the problem of necessitarianism. Let us consider a case in which we attempt to evaluate the modal status of a given proposition p, say, the proposition “Philadelphia Flyers won the Stanley Cup in 2002”. Intuitively, we would be inclined to look upon this proposition as counterfactually possible, contingently false, as the winner was Detroit Red Wings. Just as intuitively, the evaluation of the modal status of p requires correct understanding of its content. In Descartes’s philosophy, it would at least seem, this requires clear and distinct understanding. It appears that if our understanding of p were obscure and confused, we would not really know what proposition it is whose modal status we are about to evaluate. A tempting objection at this point is to claim that modal assessment of p, in Descartes’s philosophy, does not require clear and distinct understanding of p. It could be argued that modal assessment of p only requires understanding the sense of p, not seeing p as true. So, insofar as clear and distinct understanding of p involves seeing p as true, Descartes’s account of modal assessment does not, or at least should not, imply any commitment to the view that determining p’s modal status requires clear and distinct understanding of p. I submit, however, that distinctions between fully understanding the sense of a proposition, understanding a proposition clearly and distinctly, and understanding something as true, are neither clear nor unproblematic (see Wilson 1978, ch. IV), so at this point I shall assume that modal assessment in Descartes requires clear and distinct understanding and see where that assumption takes.


On the present view, then, we should have a clear and distinct understanding of the proposition “Philadelphia Flyers won the Stanley Cup in 2002” when we enter into the evaluation of its modal status. But according to the truth rule, everything we clearly and distinctly understand is assent-compelling and true. So, it seems that a prerequisite of assessing the modal status of a proposition, i.e., the requirement that its content be clearly and distinctly understood, implies that the proposition is true. Therefore, it now seems that Descartes’s truth rule prevents us from evaluating propositions as merely possible but not actually true. According to this reading, from our perspective there are no counterfactually possible propositions, no unactualized possibles. To be able to look upon a proposition as counterfactually possible, we should clearly and distinctly understand this proposition without believing it to be true. Descartes’s account of spontaneity, however, seems to preclude us from this, as we already saw.


The truth rule can be seen to have its bearing also on those propositions which we are inclined to look upon as contingently true. For example, when we enter into the assessment of the proposition “Philadelphia Flyers did not win the Stanley Cup in 2002”, we apparently should, again, have a clear and distinct understanding of that proposition. In the same way as in the previous case, clear and distinct understanding now implies the truth of the proposition, but what is more, if we accept a certain kind of interpretation of Descartes’s modal concepts at this point, we come very close to the necessity of the proposition. In general, we come very close to the necessity of propositions that we would intuitively hold contingently true. The interpretation of Descartes’s modal views referred to here is one according to which Descartes had a reductionist theory of modality, or more precisely, one according to which modalities in Descartes’s philosophy boil down to facts concerning human condition. Most notably Bennett (1994) has recently argued that Descartes is committed to the reduction of modal concepts to the constitution of the human mind. Following Alanen’s (1988) and Wilson’s (1978, 125, 127) suggestive thoughts, Bennett (1994, 646) claims that the concept of necessity (just as other modal concepts) does not refer to how things stand in reality, but to how things relate to our concepts. On Bennett’s (1994, 648) view, modalities do not have existence independently of human minds. According to Bennett’s conceptualist interpretation of Descartes’s modal theory, necessity, for instance, is ultimately reducible to compelled assent, some sort of psychological irresistibility.[7] On this interpretation, no proposition can be assessed as contingently true if we suppose that the prerequisite of modal assessment is (assent-compelling) clear and distinct understanding. If necessity reduces to compulsive assent, then, insofar as Descartes’s account of spontaneity effaces the difference between understanding and believing, the only reachable outcome of successful modal assessment is that the proposition under scrutiny is not only true but also necessary.


If the observations made above are correct, we seem to have arrived in quite a surprising outcome. Descartes’s way of struggling with the problem of freedom seems to have a strange and unwelcome consequence regarding his views on modality. His system begins to appear as necessitarian, as he seems to have no room for contingently false nor contingently true propositions.


A different route to the necessitarian worry in Descartes is Principles of Philosophy III.47, where Descartes writes that “matter must successively assume all the forms of which it is capable” (CSM I, 258, AT VIIIA, 103). This suggests that every possible state of the (material) universe occurs at some instant of time. Leibniz later claims that Spinoza, while expounding more clearly the views endorsed by Descartes in Principles of Philosophy III.47, correctly draws the necessitarian conclusion from Cartesian principles. Leibniz, thus, held that Descartes’s philosophy includes a necessitarian commitment, but arrived at the necessitarian interpretation of Descartes through considerations other than those expounded in this paper. (See Letter to Philipp, L, 273.)


3. Actualism, Necessity, and Contingency

Evidence Against the Necessitarian Interpretation

It certainly seems problematic to understand Descartes as a necessitarian philosopher. Just a brief consideration of his view of the causal origin of modalities seems to contradict the interpretation that he believed all truths to be necessary. If God has freely created all eternal truths, as Descartes claims, it appears that even these most stable truths are in some bizarre sense not necessary. After all, God could have acted in an entirely different fashion that he did, if only he had willed to do so. He was, according to Descartes (Letter to Mersenne, CSMK III, 25, AT I, 152), as we already saw, “free to make it not true that all the radii of the circle are equal—just as free as he was not to create the world.” Some scholars, perhaps most notably Frankfurt (1977), have argued that Descartes endorsed no less than universal possibilism, according to which absolutely everything, including contradictions, is possible.[8] Be this very controversial interpretation correct or not, Descartes’s view of the causal origin of modalities surely suggests some sort of attenuation of necessity, rather than any reinforcement of it.


Further evidence for the view that Descartes is not a necessitarian philosopher can also be found from the argument for mind-body dualism, built in the Sixth Meditation on grounds presented in previous Meditations. Chiefly on the basis of the Second and Fifth Meditations Descartes arrives at the conclusion that he can understand mind apart from body and body apart from mind, and finally in the Sixth he argues that clear and distinct understanding of one substance apart from another suffices for the certainty that the one excludes the other (see also Replies to Fourth Objections, CSM II, 159, AT VII, 226). In the famous passage from the Sixth Meditation, Descartes (CSM II, 54, AT VII, 78) writes:


First, I know that everything which I clearly and distinctly understand is capable of being created by God so as to correspond exactly with my understanding of it. Hence the fact that I can clearly and distinctly understand one thing apart from another is enough to make me certain that the two things are distinct, since they are capable of being separated, at least by God.


Descartes explicitly states here that two things are distinct because they are capable of being separated. A straightforward interpretation of this seems to be that Descartes regards possible separation as a sufficient condition for, and perhaps even constitutive of, real distinction, i.e., distinction that holds good between substances (see Garber 1992, 85, 89; Hoffman, 1996, 343n; Wilson 1978, 190, 207). On this view, really distinct substances do not have to be actually separate. It is enough that they are separable, capable of existing without one another. Descartes (CSM I, 213, AT VIIIA, 28) lucidly comments on this tenet in Principles of Philosophy, where he writes:


…even if we suppose that God has joined some corporeal substance to such a thinking substance so closely that they cannot be more closely conjoined, thus compounding them into a unity, they nonetheless remain really distinct. For no matter how closely God may have united them, the power which he previously had of separating them, or keeping one in being without the other, is something he could not lay aside; and things which God has the power to separate, or to keep in being separately, are really distinct.


It appears very hard to see how the dualism argument should be understood, if there was no room for contingent truths in Descartes’s philosophy.


Closely related to the dualism argument, evidence for the view that Descartes admits counterfactual possibilities can be found in his notion of substance. Being separable and hence capable of existing without one another, both mind and body meet the independence requirement of substancehood. Cartesian finite substances are entities which exist independently of other finite entities (Principles of Philosophy I.51, CSM I, 210, AT VIIIA, 24), which is to say that they can exist without other things, i.e. by themselves and without the aid of any other substance besides God (see Replies to Fourth Objections, CSM II, 159, AT VII, 226). Therefore, in addition to Descartes’s crucial premise in the dualism argument and his independence-based characterization of substancehood suggest that he was committed to the acceptance of counterfactual possibilities.


In addition to the evidence against the necessitarian interpretation of Descartes, it seems that evidence can be found for the view that he did not renounce nonactual entities. Descartes (Replies to First Objections, CSM II, 83, AT VII, 116) explicitly states that “we must distinguish possibility from necessity”, and that “possible existence is contained in the concept or idea of everything that we clearly and distinctly understand; but in no case is necessary existence so contained, except in the case of the idea of God.” And importantly, “even though our understanding of other things always involves understanding them as if they were existing things, it does not follow that they do exist, but merely that they are capable of existing” (ibid., emphases mine). To start with, these are hardly necessitarian characterizations. Furthermore, Descartes’s statement that our understanding of things only entails their possible existence, as opposed to actual existence, could be read to show that he accepted nonactual entities, or mere possibilia. Descartes also speaks of things such as winged horses and it seems that he does not want to rule out their possible existence, even if there are no such things as winged horses. For instance, he writes: “When, for example, I think of a winged horse or an actually existing lion, or a triangle inscribed in a square, I readily understand that I am also able to think of a horse without wings, or a lion which does not exist, or a triangle apart from a square, and so on” (CSM II, 84, AT VII, 117). Winged horses are conceivable, and as far as this means that there are nonactual entities, Descartes is helping himself to entities which any necessitarian philosopher would be at pains to renounce.


Contrary to the view that Descartes admitted unactualized possibles into his ontology, it has been recently argued by Alan Nelson and David Cunning and that Descartes can be interpreted as an actualist (Nelson & Cunning 1999; Cunning 2002), i.e. a philosopher who does not believe in nonactual entities. If this interpretation of Descartes’s modal metaphysics were correct, the passages in which he appears to refer to nonactual entities would be useless as evidence against the necessitarian interpretation of his philosophy.


Actualism and Possibilism

In this paper, the notion of actualism has, up to this point, simply been taken to include the renunciation of nonactual entities. However, contemporary discussions on modal metaphysics show that actualism can be understood in a number of different ways. Hence, I believe it is important to take a brief look into some recent formulations of actualism before discussing the actualist interpretation of Descartes. As this paper is primarily written for students of Descartes’s thought, familiarity with the main lines in the discussion of actualism and its challenges cannot be presumed. A word of caution is also in order: I do not intend to pursue anachronistic hypotheses to the effect that present-day views on quantified modal logic should be attributable to Descartes, but I shall consider some contemporary formulations of actualism in order to have a clearer view on the thesis Descartes is held to accept when we call him an actualist.


Salmon (1987, 56) characterizes actualism and possibilism as follows:


The doctrine that the standard quantifiers of natural language (the English words ‘everything,’ ‘something,’ etc.) are possibilist quantifiers is sometimes called ‘possibilism’, and the doctrine that they are actualist quantifiers is sometimes called ‘actualism.’


According to this formulation, the debate between actualists and possibilists concerns the domain of entities over which our quantifiers range. The actualists refuse to quantify over nonactual entities, contrary to the possibilists. A similar, and quite common, way of formulating the actualist thesis can be found in Linsky and Zalta (1994, 436):


Thesis of actualism: Everything which exists (i.e., everything there is) is actual.


According to these formulations, an actualist holds that everything that exists, exists in the actual world (see also Fitch 1996, 53). Actualism, according to this type of approach, can be seen as a metaphysical theory according to which truth of modal claims can be accounted for without quantifying over nonactual individuals or worlds. The actualists are not willing to commit themselves to such ontological extravagance as, for instance, dictated by modal realism, or genuine modal realism (see Divers, 2002, 21-22), held by David Lewis (1973, 85), who writes:


When I profess realism about possible worlds, I mean to be taken literally. Possible worlds are what they are, and not some other thing. If asked what sort of thing they are, I cannot give the kind of reply my questioner probably expects: that is, a proposal to reduce possible worlds to something else. I can only ask him to admit that he knows what sort of thing our actual world is, and then explain that possible worlds are more things of that sort, differing not in kind but only in what goes on at them.


An actualist cannot accept genuine modal realism, because a genuine realist believes there are, besides the actual one, nonactual entities over which our quantifiers irreducibly range. At the other side of the fence, a possibilist who endorses genuine modal realism has the advantage of being able to account for the truth of modal claims in a very straightforward way, treating modal operators as ontologically committing quantifiers over possible worlds, but at the expense of multiplying her ontology beyond the limits of actuality.


The distinction between genuine modal realism and the thesis that everything there is is actual calls for an important clarification concerning the notion of actuality. The need for this clarification can be seen by considering the way in which the concept of actuality can be applied in genuine modal realism. In a sense, it can be said that a genuine modal realist only accepts entities which are actual, because she holds that any given entity is actual in the world in which it exists. Unicorns, for instance, are actual in every world in which there are unicorns, and their being actual existents in those worlds accounts for the truth of the claim “It is possible that there are unicorns”. The distinction between genuine modal realism and actualism requires drawing a distinction between indexical and absolute senses of ‘actual’. According to an indexical theory of actuality, endorsed by the genuine modal realist, the reference of ‘actual’ varies depending on the context, i.e., the world, in which it is used. On the indexical view, ‘actual’ means merely ‘occurring in this world’, ‘occurring in a world we are in’, or suchlike (see Adams 1974, 214). On the other hand, when used in an absolute sense, ‘actual’ is, absolutely considered, more real than the merely possible (ibid., 215). On this view, things belonging to the actual world w* have actuality not only in relation to the inhabitants of w*, but in a much more broad sense, in relation to the inhabitants (if there are any) of all worlds. On the absolute view, ‘actual world’ could be understood as a rigid designator, whose reference does not vary by context. If understood in the way formulated, for instance, by Linsky and Zalta, actualism excludes the genuine modal realist theory only if the notion of actuality is used in its absolute sense. While discussing the hypothesis that Descartes is an actualist philosopher, I shall understand the notion of actuality, then, in the absolute sense.


Another clarificatory point is now in order. According to one formulation of actualism, one can claim that nothing but actual entities exist and still endorse possibilism. This formulation is based on the idea that the difference between actualism and possibilism concerns the question whether the quantifier ‘there are’ is existentially loaded, so to speak. Consider the following formulation by Bergmann (1996, 359n1):


Actualism is the thesis that necessarily everything that there is exists. […] Thus, actualism is opposed, for example, to Meinong’s claim that there are objects which have being but not existence.


This characterization allows that a possibilist such as Meinong, who distinguishes being from existence, can accept as trivially true the thesis that no nonactual entities exist, but still endorse the possibilist thesis that there are nonactual entities. I shall not, in what follows, understand the notions of actualism and possibilism through the distinction between being and existence. I shall use the expressions “There are no nonactual entities” and “No nonactual entities exist” as synonymous. It should be noted, though, that Descartes has been interpreted as being committed to the distinction between being and existence in his philosophy of mathematics. Anthony Kenny (1970, 692-93, 699) argues that Descartes was no less than the father of modern Platonism, who believed that the objects of mathematics depend on physical substances, not physical existents. Kenny thus claims that Descartes posited things which subsist without existing—have being without having existence. Therefore, if Kenny’s interpretation was correct, Descartes should be read as a possibilist, and Bergmann’s formulation of possibilism would be the one to use. However, I believe, and shall argue in the next section, that Kenny’s argument in favor of the Platonic reading of Descartes’s modal metaphysics is unconvincing. According to my reading, Descartes did not accept abstract Platonic substances, over and above the extended and thinking substances which comprise all there is in his dualist ontology.


The final clarificatory point I want to make concerning the notions of actualism and possibilism is related to the aforementioned topic of abstract entities, in that it concerns the ontological status of the things we posit when accounting for the truth and falsity of our modal claims. Consider the following formulation by McMichael (1983, 50):


According to the possibilists, possible worlds are concrete entities. In this respect, they are like the the concrete universe which we inhabit. […] Actualists who believe in possible worlds view them as existing abstract entities. The actual world is not actual merely in the sense that it exists—all possible worlds exist—but rather in the sense that this concrete universe corresponds to it.


According to McMichael’s formulation, modal realists—people who believe in possible worlds—can be divided into possibilists and actualists. Possibilist modal realists believe possible worlds are concrete, whereas actualist modal realists believe they are abstract. Notice that this distinction is precisely the distinction between genuine realism and actualist realism. Divers (2002, 22), for instance, writes that “genuine realism conceives of the possible worlds as a vast plurality of non-actual, concrete things, while actualist realism conceives of the possible worlds as a vast plurality of actual, abstract things.” I think this distinction is quite important when we assess the hypothesis that Descartes endorses actualism, since it seems fairly uninteresting to discuss whether Descartes accepts or denies the existence of nonactual concrete things. Calling Descartes an actualist on the ground that he does not accept nonactual concreta is very likely to be true, but it is even more likely to be very uninteresting. Genuine realism has born from the need to provide semantics for quantified modal logic, and there is no reason to suppose that Descartes would have even thought of there being nonactual concrete entities. What is interesting, however, is whether Descartes accepts actualism in the very strong sense that his ontology only contains actual concreta, nothing else. This question is especially pressing concerning the worry that Descartes might be committed to necessitarianism, since it is not obvious how a philosopher who only accepts actual concrete things can save our basic modal intuitions concerning, say, things which could happen but in fact do not.


An Actualist Reading of Descartes

Although actualism has been a topic of discussion predominantly in contemporary philosophy, actualism was not an unknown doctrine in early modern philosophy. Spinoza famously endorsed full-blown actualism, and if Descartes can be approached from an actualist angle, we might be able to argue that Spinoza was following Descartes while embracing actualism. Actualism does not, however, immediately stand out as any sort of acknowledged doctrine in Descartes’s writings; a proponent of an actualist interpretation obviously has the burden of proof over the supporters of the opposing opinion. Basically, three considerations have been set forth on the basis of which it has been argued that Descartes might well have renounced unactualized possibles (Cunning 2002). One of these considerations is textual and the remaining ones are systematic.


The textual evidence comes from the Third Meditation, where Descartes discusses the idea of God and asks what could have caused its representational content, or objective being in Cartesian terminology. He writes that “the objective being of an idea cannot be produced merely by potential being, which strictly speaking is nothing, but only by actual or formal being” (Third Meditation, CSM II, 32, AT VII, 47). Cunning’s reading of this is that Descartes denies the existence of potential being. And if he does so, it is hard to see how he could have included nonactual entities in his ontology. However, I believe it is not so clear that this passage, as it stands, shows that Descartes denies the existence of purely potential being. An alternative reading can be presented along the following lines. To start with, the topic Descartes deals with is the question what might have caused the objective being of an idea. Descartes’s position is that it cannot be caused by a pure potentiality, and the reason he offers for this is that a pure potentiality “strictly speaking is nothing”. Why does he say “strictly speaking” instead of just blatantly denying the existence of a merely potential being? I believe it is possible to interpret him as saying that a purely potential being, in so far as it is merely potential and not actual, cannot have any causal efficience. What makes a merely potential entity causally ineffective is that it does not have a suitable mode of being; unlike God, finite minds and finite bodies, it is not a concrete entity, and it is therefore causally inefficient. Thus, as it stands, the passage under scrutiny is compatible with the view that purely potential entities are causally inefficient abstract entities. However, if it could be further argued that there is no room for abstract entities in Descartes’s ontology, the case for reading him as renouncing potential beings becomes much more convincing. And indeed, the nominalist, or rather, conceptualist, tendencies in Descartes’s philosophy seem to provide extra support for the proponent of this reading. For instance, in Principles of Philosophy I.58, entitled as “Number and all universals are simply modes of thinking”, Descartes (CSM I, 212, AT VIIIA, 27) writes as follows:


In the same way, number, when it is considered simply in the abstract or in general, and not in any created things, is merely a mode of thinking; and the same applies to all the other universals, as we call them.


Now, if merely potential beings are not concrete, and if abstract entities are merely modes of our thought, the upshot seems to be that nonactual entities only exist as modes of our minds and do not have a first-class residence in Descartes’s dualist ontology. A winged horse, for instance, exists only as mode of our thought if no created thing has the property of being a winged horse. The essence of this nonactual zoological species does not exist in an independent abstract universe of essences, but is reducible to the ways of our thinking. In fact, Descartes seems to accept even a stronger claim that all essences are nothing but modes of our thought. In one of his key letters on voluntarism, he identifies eternal truths with essences, telling Mersenne that “it is certain that he [i.e. God] is the author of the essence of created things no less than of their existence; and this essence is nothing other than than the eternal truths” (CSMK III, 25, AT 1, 152). Then, in Principles of Philosophy, he says:


All the objects of our perception we regard either as things, or affections of things, or else as eternal truths which have no existence outside our thought (CSM I, 208, AT VIIIA, 22).


The identification of essences and eternal truths, together with the claim that eternal truths have no existence outside our thought, amount to the view that all essences are modes of our thought.


In understanding essences as modes of our thought, Descartes appears as a defender of conceptualism and perhaps as some sort of precursor of mathematical intuitionism, rather than as a defender of Platonic realism and a forerunner of mathematical logicism (of these concepts, see e.g. Quine 1953, 14-15). This interpretation is in a sharp contrast with Kenny’s view that Descartes, indeed, is a Platonist about essences. However, I am not convinced by Kenny’s argument in favor of the Platonist interpretation. According to Kenny (1970, 696), Descartes is committed to hold that essences are something distinct from God, because God stands in a causal relationship to them, being their efficient cause. I find this plausible, because if essences were somehow located in God, it would be strange that Descartes calls them creatures (see also Cunning 2002). Geometrical essences, for instance, are something distinct from God, but Descartes holds that no material object exactly corresponds to them, because actual bodies are always too irregular, as Kenny (1970, 694) rightly points out. Indeed, when responding to Gassendi’s nominalist and abstractionist view of essences (see Fifth Set of Objections, CSM II, 222-23, AT VII, 320-21), Descartes (Fifth Set of Replies, CSM II, 261, AT VII, 380) argues that the essence of a triangle—or of any other geometrical figure—cannot be abstracted from particular confrontations with material objects. Now, as far as I can see, Kenny’s argument for the Platonic interpretation of Descartes is this: He claims that since geometrical essences must be distinct from God, but irreducible to material objects, the only remaining ontological alternative for Descartes is to hold that those essences are abstract Platonic entities. Although Kenny’s premises are plausible, I do not see how the conclusion should follow. The premises are, I believe, fully compatible with an interpretation according to which Descartes endorses a conceptualist view of essences, rather than Platonic realism. According to the conceptualist view (especially Bennett 1994) Descartes understands modalities—and hence essences—to be in some sense a function of the constitution of our minds. According to the conceptualist reading, Descartes’s God created modal truths in making us the way we are (see Bennett 1994, 646). The objects of our mathematical intuitions are, on this view, innate principles or structures of thinking which have no existence independent of our minds; to deny their mind-independent existence is not, however, to say that they are randomly subjective or arbitrary (Alanen 1999, 106). Human minds are creatures distinct from God, and therefore essences are as well. Kenny’s premises thus allow at least both the Platonic and the conceptualist interpretation, and I believe Descartes’s explicit statement that eternal truths have no existence outside the mind strongly speaks for conceptualism rather than Platonism.


On behalf of the Platonic interpretation it has to be said that it has no difficulty in accommodating with Descartes’s view that mathematical truths and essences are eternal, or as Descartes also says, immutable (e.g. Fifth Meditation, CSM II, 44-45, AT VII, 64). Eternally existing Platonic forms guarantee the eternity of eternal truths, but it is not so obvious how the conceptualist interpretation can account for their eternity. Human mind is, clearly, a contingent being which can be altered by God. Therefore, a defender of the Platonist interpretation could argue that the conceptualist interpretation contradicts Descartes’s view that essences are, in a very robust sense, immutable. She might argue that the conceptualist Descartes could, at best, hold that eternal truths are actually unchanging, but unable to maintain that they are unchangeable. However, Descartes seems to equate ‘God is immutable’ with ‘God always acts in the same way’ (see The World, CSM I, 96, AT XI, 43; see also Bennett 1994, 665), and he writes of geometrical essences that “since they are always the same, it is right to call them immutable and eternal” (Fifth Set of Replies, CSM II, 262, AT VII, 381). This strongly suggests that Descartes held eternal truths to be eternal only in the sense that their truth values do not change. The best the conceptualist Descartes could say about the eternity of eternal truths, indeed, seems to be just what Descartes really says.[9]


Let us now return to the evidence offered for the actualist interpretation. The first systematic piece of evidence is drawn from Descartes’s parsimonious dualistic ontology and his theory of conceptual distinctions. For Descartes, there are only two kinds of created substances—minds and bodies—and their modes. As he states in Principles of Philosophy I.48 (CSM I, 208, AT VIIIA, 22), he recognizes only two ultimate classes of things: intellectual or thinking things, i.e., those which pertain to mind or thinking substance; and material things, i.e. those which pertain to extended substance or body. Now, Cunning contends that if the purported mere possibles were just created substances, then presumably they would have to be actual. To me this sounds very plausible. The challenger of the actualist interpretation might, of course, suggest that both of the two fundamental ontological classes of things in Descartes’s dualism contain entities having actual existence and entities having possible existence. But this suggestion leads to a problem. Cunning argues that Descartes could not adhere to his theory of the conceptual distinction between a substance and its attributes, if he postulated both actually existing and merely possibly existing entities within one fundamental ontological class. An important premise in this argument is that Descartes believes all creatures have possible existence. This premise seems plausible, since Descartes (CSM II, 117, AT VII, 166) declares in the Second Replies that “Possible or contingent existence is contained in the concept of a limited thing”. The implication of this view is that an actually existing creaturely thing has possible existence, and there should be some sort of explanation as to how actual existence and possible existence differ in this case. Cunning’s argumentation also relies on the view that, according to Descartes, the existence of a thing is identical to the thing itself. Evidence for this claim comes from a letter to an unknown correspondent, where Descartes (CSMK III, 280-81, AT IV, 350) writes, for example, that the essence of a triangle which exists outside thought is in no way distinct from the existence of it. Finally Cunning (2002) states that “If the thing’s existence is just identical to that thing itself, then the thing’s possible existence is identical to the thing and the thing’s actual existence is identical to the thing. That is, a thing’s possible existence just is its actual existence.” The bearing of this argument is that if Descartes wants to make a distinction between possible and actual existence of a created thing, he must abandon his theory of conceptual distinction. For the theory of conceptual distinction would dictate that possible existence is just another name for actual existence and therefore we would arrive at actualism. I am not quite convinced of the cogency of this particular argument by Cunning, but regarding present purposes, and since more convincing evidence for the actualist interpretation has already been offered, I am more interested in the implications and developments of the actualist interpretation than the ultimate credibility of this particular argument.


The second systematic evidence presented for the actualist interpretation is based on Descartes’s view of God’s absolute simplicity. In several passages Descartes (e.g. Third Meditation, CSM II, 34, AT VII, 50; Replies to Second Objections, CSM II, 98, AT VII, 137) insists that God is a simple being, that there is no priority between God’s intellect and will (e.g. Letter to Mesland, CSMK III, 235, AT IV, 119), and that God’s willing, understanding and creating are all the same thing without one being even conceptually prior to the other (Letter to Mersenne, CSMK III, 26, AT I, 153). From the identity of God’s understanding and will it follows that whatever God understands he also wills and creates. Lest we be forced to sacrifice God’s omniscience, unactualized possibles, if they exist, should be thought as objects of God’s understanding. Nevertheless, that which is an object of God’s understanding is created and made actual. Cunning puts forward, I think plausibly, that if Descartes is seriously committed to the identity of God’s intellect and will, it is difficult to see how he can also posit nonactual entities.


Supposing that the actualist interpretation can be persuasively presented as an interpretive option regarding Descartes’s modal metaphysics, as I am inclined to hold, we should be able to present the dualism argument in a way that does not include reference to possible separation as a ground for the real distinction between mind and body. We should also be able to provide an account as to what Descartes means when he distinguishes possibility from necessity. Again, there should be a satisfactory answer to the question how the actualist interpretation can be combined with Descartes’s voluntaristic view of the causal origin of modality. If all this can be done and we opt for the actualist interpretation, we should finally also ask what impact the actualist line of thought has on the worry that Descartes might be committed to necessitarianism.


Assessing the Evidence for Possibilism and Overcoming the Necessitarian Worry

For Descartes (Replies to Fourth Objections, CSM II, 156, AT VII, 221-22), it suffices for establishing a real distinction “that two things can be understood as ‘complete’ and that each one can be understood apart from the other”, where the notion of complete thing means “a substance endowed with the forms or attributes which enable me to recognize that it is a substance.” Substances are ontologically independent (Principles of Philosophy I.51, CSM I, 210, AT VIIIA, 24), and therefore complete things are ontologically independent. As was already pointed out, a seemingly natural way of reading Descartes’s dualism argument is that a counterfactually possible separateness indicates and is constitutive of the fact that mind and body are complete independent entities, or in other words, really distinct substances.


This way of understanding the dualism argument should bother the heads of those who are inclined to accept the actualist interpretation. And indeed, Cunning believes that to view counterfactually possible separateness as the indication of the fact that mind and body are ontological indepencent is to put the cart ahead of the horse. Possible separateness, he holds, does not indicate real distinction, nor is constitutive of it. Quite the contrary, as Marleen Rozemond has argued, the separability of mind and body can be seen as a consequence of the fact that mind and body are really distinct. As Rozemond (1998, 5) points out, in the Second Replies Descartes discusses separability as a sign of real distinction and, indeed, seems to consider it as an insufficient criterion. The objectors had argued that Descartes has failed to rule out the possibility of a thinking body. In his reply, Descartes (CSM II, 95, AT VII, 132-3) compares two signs of real distinction: on the one hand, clear and distinct understanding of one thing without another, and on the other hand, ability of one thing to exist without another. Interestingly, Descartes describes understanding one thing apart from another as his own criterion and states that a more reliable criterion cannot be provided. If anything is to serve as a criterion for a real distinction, it has to be applicable, in the sense that we should be able to know when then criterial features obtain. If separability is a criterion for real distinction, we should be able to tell with certainty whether or not given things can exist apart from each other. Further, Descartes holds that separability is not in this sense a certain sign of real distinction. Finally, he boldly states that “if the proposed criterion for a real distinction is to be reliable, it must reduce to the one which I put forward” (ibid., emphasis mine). I am inclined to believe that this strongly supports the view that Descartes believed complete understanding of one thing apart from another, not the separability of one thing and another thing, to be a criterion for their real distinction. Therefore, the dualism argument can, it seems, be interpreted without referring to unactualized possibilities, and if this is the case the dualism argument does not provide systematic philosophical grounds against the actualist interpretation.


What kind of account can the defender of the actualist interpretation offer for the passages in which Descartes quite explicitly contrasts necessity with possibility? For example, what can we make of the view that possible, but not necessary, existence is contained in the concept of everything we clearly and distinctly understand? (See Replies to First Objections, CSM II, 83, AT VII, 116.) What else could this show than the fact that Descartes posited unactualized possibles into his ontology? An actualist interpretation has been attempted (Cunning 2002). To start with, it has been pointed out that in describing the kind of existence had by created things, Descartes uses the terms ‘possible existence’ and ‘contingent existence’ interchangeably. As Descartes (CSM II, 117, AT VII, 166) writes in the Second Replies, “Possible or [sive] contingent existence is contained in the concept of a limited thing, whereas necessary and perfect existence is contained in the concept of a supremely perfect being.” Again, in the Notae, “existence is contained in the concept of God—and not just possible or [vel] contingent existence, as in the ideas of all other things, but absolutely necessary and actual existence” (CSM I, 306, AT VIIIB, 361). The original Latin text has sive in the former and vel in the latter passage, and especially the use of sive supports the interchangeability of ‘possible’ and ‘contingent’ (see Nelson & Cunning 1999, 141-42). Now, if ‘possible’ and ‘contingent’ are interchangeable, we are further led to ask how we should understand contingency. The supporters of the actualist interpretation have an important restriction concerning the way in which they interpret Descartes’s view of contingency. Namely, they should not include reference to nonactual entities in their analysis. The following actualist account has been suggested: “If contingent existence is just the kind of existence had by beings that depend for their existence on God’s will, then the fact that a thing has possible existence in Descartes’ ontology does not suggest that the thing does not actually exist” (Cunning 2002). On this view, all things having possible existence actually exist, but their existence is entirely dependent on God. Possible existence is understood as nothing else than actual existence of dependent beings, and necessary existence, in turn, is nothing else than actual existence of independent beings. According to this analysis, the notions of ontological dependence and independence are more fundamental than the notions of contingency and necessity. However, we should now further ask how we are to understand the notions of ontological dependence and independence, since they are employed in the analysis of the notions of contingency and necessity. If the strategy of avoiding any reference to unactualized possibilities is to understand possibility in terms of contingency and, further, contingency in terms of dependence, the analysis of dependence should not contain such reference either. The notion of ontological dependence should not be analyzed by using modal concepts in any robust metaphysical sense. The actualist line of reasoning thus leads us to look upon modal concepts as very thin, perhaps even useless or redundant.


Indeed, Cunning has argued with Nelson (1999, 137, 140) that in addition to not admitting modalities into his ontology and having no use for a theory of modalities, Descartes used modal language in a way that should not be understood as referring to metaphysical modalities, but instead as serving other purposes. But what do the apparent modal terms refer to, if not to metaphysical modalities? What, indeed, are metaphysical modalities, to which Descartes’s apparent modal language supposedly does not refer to? As I understand Nelson and Cunning, terms such as ‘possible’ and ‘necessary’, on their interpretation of Descartes, do not refer to modal facts whose existence is independent of the human mind. On their view, Descartes’s apparent modal terms do not refer to objective modalities, but instead they have some other function in his philosophical language. If, then, there are passages in which Descartes intends his apparent modal language to have a metaphysical import, the modal terms he uses in these contexts should not be interpreted as having any modal force. Instead, they should be understood as describing some non-modal metaphysical matter, a matter whose analysis does not include reference to modal concepts.


One of the purposes that Descartes’s apparent modal terms serve, according to the actualist interpretation, has already been pointed out: sometimes Descartes uses the concept of possibility while discussing the contingent existence of dependent beings. The other uses can be seen to have an epistemic character. Descartes might write, for example, that body can exist, if we have not clearly and distinctly perceived that it does not exist (ibid.) According to this type of epistemic reading, propositions whose negations we have not clearly and distinctly perceived, are possible. Finally, modal language can also be used to express confused and false thinking, where modal terms are, again, of an epistemic character. One might say, for instance, that it is possible to square the circle if one does not know modern group theory (ibid.) On the view endorsed by Nelson and Cunning (1999, 138n1), Descartes had no more than what they call a no-theory theory of modality, for he had systematic reasons for denying that any modal theory is required. Descartes is thus held to be a proponent of a kind of redundancy view or deflationary view of metaphysical modalities. When he intends his seemingly modal language to have an immediate metaphysical bearing, he is discussing the (non-modal) issue of ontological dependence of finite beings or ontological independence of an infinite being, and at the other times this language should be understood through epistemic terms.


The remaining evidence against a necessitarian interpretation of Descartes’s philosophy is his voluntaristic view of the causal origin of eternal truths. The supporters of the actualist interpretation should be able to give an account as to how their interpretation fits with Descartes’s voluntarism. Interestingly, there is no difficulty of reconciling the actualist interpretation with Descartes’s view of the eternal truths as dependent on God. The proponent of the actualist interpretation can hold that eternal truths are dependent on God and in this sense (non-modally) contingent. However, the actualist, or deflationarist, line of thought does not entail that Descartes thought contradictions to be in any robust metaphysical sense possible, because the actualist view includes the thought that Descartes excluded metaphysical modalities from his system. And of course, contradictory propositions are not possible in the epistemic sense either, because we clearly and distinctly perceive their negations. Therefore, the actualist interpretation does not water down voluntarism, even if it denies that Descartes held contradictions to be metaphysically, or in any other sense, possible. Any interpretation which has resources to maintain this combination has, I believe, considerable merits.


What about the worry that Descartes is committed to necessitarianism? Already on the basis of the discussion above we can see that the deflationarist interpretation does not lead to the view that Descartes is a necessitarian. Both necessitarianism and universal possibilism, I presume, are doctrines which acknowledge metaphysical modalities. According to a necessitarian, all truths are metaphysically necessary, whereas a universal possibilist endorses the metaphysical possibility of any proposition. So, as far as Descartes does not accept metaphysical modalities, the attempt to classify his thought as either universal possibilist or necessitarian seems misplaced.


I find this result quite interesting, because, on the face of it, actualism prima facie points towards necessitarianism rather than helps to account for our intuitions of possibility. For instance, contemporary actualists typically are not necessitarians, but, indeed, they strive to argue that intuitions concerning contingency are compatible with the denial of mere possibilia. When a contemporary modal metaphysician, who does not want to arrive at necessitarianism, faces the task of analyzing our ordinary modal beliefs, she should provide semantics both for propositions which concern things which could not be otherwise and propositions which concern things which could exist (or events which could happen, facts which could obtain, etc.) but which in fact do not. The celebrated and straightforward way to go—understanding the modal concepts included in these propositions as quantifiers over possible worlds—enables her to make the intuitive distinctions between impossibilities, necessities, contingent truths, and contingent falsities. Nevertheless, if our contemporary modal metaphysician strives to follow her intuition that everything there is is actual, she has to make a choice between three alternatives: (i) she can argue, contrary to Quine’s (1953, 13) famous view, that quantification does not involve ontological commitment; (ii) she can formulate semantics for modal propositions without quantifying over possible worlds; (iii) she can provide an account on which the commitment to possible worlds is metaphysically innocuous. Whichever route she takes, she is confronted with the challenge of arguing that her actualist analysis of modal statements is consistent with our intuitions of contingency. According to the actualist interpretation of Descartes’s modal views, Descartes has resources to carry out an analysis of this sort.


3. Closing the Stage

We may say that the actualist interpretation sheds useful light on the difficulty of understanding what modal values truths are capable of possessing in Descartes’s philosophy. The difficulty is highlighted by the apparent implications of, on the one hand, his discussion of clarity and distinctness, and, on the other hand, his view of eternal truths as products of God’s creative acts of will. The former suggests the necessity of all truths, whereas the latter points towards the opposite direction. If the actualist interpretation I have been discussing here is plausible, Descartes’s views on modality express a fascinating blend of necessitarianism and universal contingentism: Metaphysically speaking, all truths are non-modally contingent, whereas epistemically speaking every proposition we assess as true is necessary. And as far as necessitarianism is a doctrine according to which all truths are metaphysically necessary, Descartes endorses no such doctrine.


Abbreviations and Bibliography


AG = Leibniz, G. W. Leibniz: Philosophical Essays, ed. R. Ariew and D. Garber. Indianapolis: Hackett, 1989.


AT = Descartes, R. Oeuvres de Descartes, 11 vols., ed. C. Adam and P. Tannery. Paris: Vrin, 1996. 


CSM = Descartes, R. The Philosophical Writings of René Descartes, 2. vols., ed. J. Cottingham, R. Stoothoff, and D. Murdoch. Cambridge: Cambridge University Press, 1984 & 1985.


CSMK = Descartes, R. The Philosophical Writings of René Descartes, vol. 3, ed J. Cottingham, R. Stoothoff, D. Murdoch, and A. Kenny. Cambridge: Cambridge University Press, 1991.


E = Spinoza, B. Ethics. In Spinoza: Ethics, Treatise on the Emendation of the Intellect, and Selected Letters, trans. S. Shirley. Indianapolis: Hackett, 1992.


L = Leibniz, G. W. Philosophical Papers and Letters, ed. L. E. Loemker. Dordrecht: Reidel, 1969.


THN = Hume, D. A Treatise of Human Nature. London: Everyman, 1911.






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Alanen, L. 1999. ‘Intuition, Assent and Necessity: The Question of Descartes’s Psychologism’, Norms and Modes of Thinking in Descartes, ed. T. Aho and M. Yrjönsuuri. Acta Philosophica Fennica 64: 99-121.


Bennett, J. 1990. ‘Truth and Stability in Descartes’s Meditations’, Canadian Journal of Philosophy 16 (supp. vol.): 75-108.


Bennett, J. 1994. ‘Descartes’s Theory of Modality’, The Philosophical Review 103: 639-67.


Bennett, J. 1996. ‘Spinoza’s Metaphysics’, The Cambridge Companion to Spinoza, ed. D. Garrett, 61-88. Cambridge: Cambridge University Press.


Bergmann, M. 1996. ‘A New Argument from Actualism to Serious Actualism’, Noûs 30: 356-59.


Carriero, J. 1990. Descartes and the Autonomy of Human Understanding. New York: Garland.


Carriero, J. 1991. ‘Spinoza’s Views on Necessity in Historical Perspective’, Philosophical Topics 19: 47-96.


Cunning, D. 2002. ‘Descartes’s Modal Metaphysics’, Stanford Encyclopedia of Philosophy (


Curley, E. 1975. ‘Descartes, Spinoza, and the Ethics of Belief’, Spinoza: Essays in Interpretation, ed. E. Freeman and M. Mandelbaum, 159-89. La Salle: Open Court.


Curley, E. 1984. ‘Descartes on the Creation of the Eternal Truths’, The Philosophical Review 93: 569-97.


Curley, E. 1988. Behind the Geometrical Method: A Study of Spinoza’s Ethics. Princeton: Princeton University Press.


Divers, J. 2002. Possible Worlds. London: Routledge.


Doney, W. 1955. ‘Descartes’s Conception of Perfect Knowledge’,  Journal of the History of Philosophy 8: 387-403.


Fitch, G. W. 1996. ‘In Defense of Aristotelian Actualism’, Philosophical Perspectives 10: 53-72.


Frankfurt, H. 1968. ‘Descartes’s Validation of Reason’, Descartes: A Collection of Critical Essays, ed. W. Doney, 209-26. London: Macmillan.


Frankfurt, H. 1977. ‘Descartes on the Creation of the Eternal Truths’, The Philosophical Review 86: 36-57.


Garrett, D. 1991. ‘Spinoza’s Necessitarianism’, God and Nature: Spinoza’s Metaphysics, ed. Y. Yovel, 191-218. Leiden: E. J. Brill.


Garber, D. 1992. Descartes’ Metaphysical Physics. Chicago: The University of Chicago Press.


Gaukroger, S. 1995. Descartes: An Intellectual Biography. Oxford: Oxford University Press.


Geach, P. T. 1973. ‘Omnipotence’, Philosophy 48: 7-20.


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Gewirth, A. 1970. ‘The Cartesian Circle Reconsidered’, Journal of Philosophy 67: 668-85.


Hoffman, P. 1996. ‘The Unity of Descartes’s Man’, Philosophical Review 95: 339-70.


Kajamies, T. 1999. ‘The Concept of Power and the Eternity of the Eternal Truths in Descartes’, The Southern Journal of Philosophy 37: 189-200.


Kajamies, T. 2004. ‘Mais sa volonté est libre: Some Motives for Modal Voluntarism’, SATS: Nordic Journal of Philosophy 5: 105-18.


Kenny, A. 1970. ‘The Cartesian Circle and the Eternal Truths’, Journal of Philosophy 67: 685-700.


Kenny, A. 1972. ‘Descartes on the Will’, Cartesian Studies, (ed. R. J. Butler) 1-31. Oxford: Blackwell.


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Nelson, A and D. Cunning. 1999. ‘Cognition and Modality in Descartes’, Norms and Modes of Thinking in Descartes (ed. T. Aho and M. Yrjönsuuri). Acta Philosophica Fennica 64: 138-53.


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[1] In this paper I shall work under the assumption that Spinoza is a necessitarian. It should be noted, however, that although it is unquestionable that Spinoza is a causal determinist, there is no consensus among scholars concerning the question whether Spinoza should be interpreted as a necessitarian philosopher. The main interpretive options seem to be: (i) Spinoza is consistently committed to necessitarianism; (ii) he is inconsistently committed to both necessitarianism and its denial; (iii) he is consistently committed to the denial of necessitarianism; (iv) he is committed to neither necessitarianism nor its denial. (Garrett 1991, 191-92; see also Bennett 1996, 75.)  According to Bennett (1996, 76), the only way for an explanatory rationalist to explain the occurrence of the causal chain is to claim that the entire chain is absolutely necessary. This view sounds very strong, for it suggests that an explanatory rationalist has no way of avoiding necessitarianism.


[2] In Descartes’s philosophy, the denial of God-independent standards leads to the denial of explanatory rationalism. Not so in Spinoza; his explanatory rationalism is consistent with the denial of standards independent of God, because Spinoza’s God acts from the necessity of its own nature (E1p17c2)—necessity which provides the ultimate explanation of all things. In Ep33s2 Spinoza notes that to subject, á la Descartes, all things to the indifferent will of God is nearer to the truth than the view that God acts for the sake of the good. This shows that Spinoza prefers Descartes’s voluntarism to Leibniz’s intellectualism although he believes that voluntarism, too, is untenable.


[3] Descartes writes lucidly about automatons, human agents, and praise in Principia I.37: “The supreme perfection of man is that he acts freely or voluntarily, and it is this which makes him deserve praise or blame. The extremely broad scope of the will is part of its very nature. And it is a supreme perfection in man that he acts voluntarily, that is, freely; this makes him in a special way the author of his actions and deserving of praise for what he does. We do not praise automatons for accurately producing all the movements they were designed to perform, because the production of these movements occurs necessarily. It is the designer who is praised for constructing such carefully-made devices; for in constructing them he acted not out of necessity but freely. By the same principle, when we embrace the truth, our doing so voluntarily is much more to our credit than would be the case if we could not do otherwise.” (CSM I, 205, AT VIIIA, 18.)


[4] It is obvious that Descartes saw a close connection between the method of leading a virtuous life and the method of pursuing the truth (See Fourth Meditation, CSM II, 41, AT VII, 58). Descartes’s theory of error is structurally similar to his theory of sin: both error (e.g. Fourth Meditation, CSM II, 38, AT VII, 55) and sin (e.g. Letter to Mesland, CSMK III, 234, AT IV, 117) are based on lack of knowledge. The reason why the theory of sin is absent from the Meditations, Descartes tells Mesland (ibid.), is that he did not want to get involved in theological controversies and instead wanted to stay within the limits of natural philosophy. His basic view of evil-doing, the view that we cannot sin unless our will is led by obscure and confused ideas, goes back to Aristotle’s Nicomachean Ethics: “every wicked man is ignorant of what he ought to do and what he ought to abstain from” (1110b28). Kenny (1972, 22-23) points out that Descartes expressed his view of sin as early as in 1637. Indeed, Descartes writes to Mersenne (27 April 1637) that “voluntas non fertur in malum, nisi quatenus ei sub aliqua ratione boni repraesentatur ab intellectu” and “omnis peccans est ignorans” (AT I, 366).


[5] Hume later made a distinction between indifference and spontaneity when he insisted that we should distinguish “betwixt the liberty of spontaneity, as it is called in the schools, and the liberty of indifference; betwixt that which is opposed to violence, and that which means a negation of necessity and causes. The first is even the most common sense of the word; and as it is only that species of liberty which it concerns us to preserve, our thoughts have been principally turned towards it, and have almost universally confounded it with the other.” (THN, Bk. 2, Pt. 3, Sec. 2, Para. 1) Hume’s notion of indifference is, however, different from Descartes’s notion. Whereas Hume’s indifference seems to mean power to do or not to do something (see Kenny 1972, 17, 24), Descartes’s notion of indifference has to do with lack of reasons pushing the will, or reasons balancing each other out or pushing towards contrary directions. Indeed, Descartes explicitly admits that our will has the power of determining us and says that it makes no difference to this power whether it is accompanied by indifference or not (Letter to Mesland, CSMK III, 234, AT IV, 116; see also Letter to Mesland, CSMK III, 245, AT IV, 173). So, Descartes also accepts the Humean sense of indifference in addition to his own. The main difference, I think, between Hume’s notion and Descartes’s notion is that whereas Hume thought freedom of indifference to be a power to do otherwise, Descartes rather thought indifference to be a state of mind during which this power may be employed. To use the term ‘Humean indifference’ is perhaps a bit misleading, since the notion of indifference as power of determining oneself is already present in scholastic philosophy. Jesuit philosophers, following Luis Molina, understood freedom in terms of the indifference Hume refers to. (See Sleigh, Chappell, and Della Rocca, 1998, 1209.) According to Kenny (1972, 17), the contrast between freedom of spontaneity and freedom of indifference has survived throughout the history of philosophy.


[6] It should be noted that, just as the notion of indifference, the notion of spontaneity was not Descartes’s invention. In one of his letters (CSMK III, 179, AT III, 360) he refers to the theologian Guillaume Gibieuf and tells his correspondent Mersenne that while setting forth the view that indifference is a defect rather than a perfection of freedom he has not written anything which is not in accord with Gibieuf’s De Libertate Dei et Hominis, a book on which Gibieuf worked throughout the 1620’s and which was published in 1630 (Gaukroger 1995, 138). He seems to consider Gibieuf’s view that the essence of freedom is spontaneity as authoritative and is confident that his own position on free will can be successfully defended by views provided by Gibieuf.


[7] A clear statement of the view that Descartes’s modal concepts reduce to psychological facts can be found in Larmore (1984, 66), who writes about Descartes’s “subordination of logic to a psychological fact”. And according to Bennett’s (1994, 647) reading of Descartes, “it is absolutely impossible that p” means the same as “no human can conceive of p’s obtaining while having p distinctly in mind”, where the ‘no human can’ is not understood as involving logical modalities, but instead is understood in causal and psychological terms. This seems to be an outright expression of a psychologistic reduction of modalities. Bennett elsewhere (1990), however, labels his view as a guarded (not quite full-blooded?) version of the psychologistic view of clarity and distinctness.


[8] Fortunately, there is only one passage which, unfortunately, directly supports the view that Descartes was committed to universal possibilism. In his letter to Mesland, Descartes (CSMK III, 235, AT IV, 118) writes that “God cannot have been determined to make it true that contradictories cannot be true together, and therefore […] he could have done the opposite”. I am inclined to believe that this passage should be taken as a somewhat careless way of expressing God’s independence of the eternal truths. Because of the seemingly close connection between Descartes’s voluntaristic view of the origin of modalities and universal possibilism, some scholars have argued that modal voluntarism is inconsistent (Geach 1973, 11; Curley 1988, 42). Again, some scholars have associated Descartes’s system with a some sort of irrationalism. Frankfurt (1977, 54), for example, writes that “Descartes vision […] is that the world may be inherently absurd”, and that the rationality we experience “may be nothing more than a conveniently collective form of lunacy, which enables those who suffer from it to communicate with each other, but which isolates them all equally from what is ultimately real”. If Frankfurt’s extreme view is correct, Descartes not only fails to be an explanatory rationalist, but what is more, is driven to a position exhibiting outright irrationalism.


[9] I have argued elsewhere that there is also a way to defend the conceptualist interpretation of Descartes’s modal views by taking a close look of his earliest proclamations of modal voluntarism (see Kajamies 1999).





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Dr. Timo Kajamies teaches philosophy at the University of Turku, Finland. His research centers mainly on seventeenth-century and contemporary epistemology.


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