1 The Creation of Eternal Truths
Descartes’s decision not to complete the Regulae has no obvious explanation. The text breaks off abruptly in the planned third part as it approaches the task of tackling “imperfectly understood” questions – such as the nature of magnetism – which Descartes hoped to reduce to mathematical problems concerning magnitudes and proportions, preliminarily delimiting the body of empirical data to be examined and eliminating any element foreign to them.1 The fact is that the laws of physics – as Descartes knew since first broaching dynamics – cannot be interpreted solely in terms of “simple natures” known through direct intuition; they require an external foundation based on the existence of a “lawgiver”, which in turn can only be secured through a metaphysical reflection.
This may be the hidden background of an important passage in Descartes’s letter to Mersenne dated 15 April 1630, regarding “some other treatises” begun “when I was in Paris” and then left unfinished – no doubt the Regulae and perhaps the Studium bonae mentis.2 Descartes gives Mersenne “the reason” for this renunciation: “when I was working on them I gained a little more knowledge than I had when I started them, and wanting to take this into account, I was forced to start a new project, one a little larger than the first; in the same way that, if someone who started building a house for himself acquired some unexpected wealth and changed his status, such that the building he started was now too small for him, we would not blame him if we saw him start another house more suitable to his fortune”.3
This is the first of a long series of architectural metaphors that will multiply in Descartes’s subsequent writings, starting with the Discourse on the Method. However, despite Descartes’s typical euphemistic tone, one cannot help but interpret his words as the recognition of a philosophical crisis: the house of the Regulae had become too small while he was in the process of building it, which forced him to launch another construction “more suitable to his fortune” – that
Neither thematised nor designated explicitly in the Regulae, “metaphysics” suddenly and almost brutally emerges in the Cartesian corpus, from which, until that point, it had been entirely absent. The first symptom of this metaphysical awakening had already appeared in July 1629, when Descartes wrote to Guillaume Gibieuf that he had begun work on a “little treatise” – a work that, given the profession of his correspondent, can reasonably be supposed to concern God and the human soul. Gibieuf, a doctor in theology at the Sorbonne, was about to publish a significant book on the freedom of God and man.4 On 15 April 1630, Descartes informed Mersenne that metaphysics was the subject he had “studied above all others” since arriving in the Netherlands, and that it was through metaphysics that he had been able to discover the foundations of physics.5
This lost metaphysical treatise, begun in 1629 at Franeker in Friesland – Descartes’s first Dutch residence – is known to have occupied him for several months.6 His stated aim, as he later wrote to Mersenne, was to demonstrate metaphysical truths, in particular the existence of God and the immortality of the soul, in order to silence the impudence of the atheists (against whom Mersenne himself had written a powerful volume in 1624: L’Impiété des déistes, athées, et libertins de ce temps).7
In his 15 April 1630 letter to Mersenne, Descartes makes a remarkable claim. He asserts that his treatise aims to demonstrate the existence of God
And yet, under the pressure of Mersenne’s insistent doubts and questions (which we can only infer, since nearly all his letters to Descartes have been lost), something soon begins to emerge. Three letters are important in this regard, all addressed to Mersenne in the spring of 1630 – specifically on 15 April, 6 May, and late May or early June. Each of these letters focuses on the issue of God’s power over so-called “eternal truths,” and over mathematical truths in particular.
It is solely by divine decree, Descartes asserts, that it is true that “all lines drawn from the centre to the circumference [of a circle] are equal”.10 Eternal truths, therefore, are eternal only in an improper sense (“the truths that you call eternal”),11 since in reality they depend upon God. To these examples drawn from mathematics, others will later be added, until – in several texts from the 1640s – Descartes comes to claim that all necessary truths depend on God, including the axioms of both ethics and metaphysics.12
On this matter, Descartes’s position is virtually without precedent in the history of philosophy – and also without real successors, except for a few loyal Cartesians in the decades immediately following his death.13 For Descartes, it
Some philosophers, Descartes observes, claim that “even if God did not exist, these truths would still be true”; but that inverts the proper order of things: “the existence of God is the first and the most eternal of all the truths there can be, and the only one from which all the others flow”.14 Otherwise, one is committed to atheism: for to deny the omnipotence of God is, ultimately, to deny His very existence. One must never say, then, that God could not do something; at most, we may say that an angel “could not do it”.15
Although Descartes adopts here a position opposed to the entire preceding Western metaphysical tradition, he seems to direct his criticism above all against a specific adversary, without ever naming him explicitly: the Jesuit Francisco Suárez (1548–1617), author of the Disputationes metaphysicae (1597), the most important and influential metaphysical work of late scholasticism. It was Suárez who had written that even if, per impossibile, God did not exist, the “eternal truths” would nonetheless remain true. Obviously, Suárez’s claim was intended as a counterfactual statement, far from any atheistic implications, but it was perfectly clear in positing the independence of the “eternal truths” from God.16
In stark contrast to Suárez, Descartes assimilates truths to created things, subjecting them entirely to divine power. In his letter of late May (or early June) 1630, he explicitly states that God “established” eternal truths with the same kind of causality by which He created everything else. He even adds that the eternal truths “are something” – thereby attributing to them a certain
The metaphysical theory of the creation of eternal truths arises in direct relation to physics – that is, to the strictly mechanistic physics towards which Descartes decisively reorients the focus of his inquiry around 1629–1630. This connection is clearly attested in the 1630 correspondence: “I could not have discovered the foundations of physics if I had not sought them by this path” (that is, by way of metaphysics).18 Cartesian physics is founded on the certainty that reality has a mechanical structure, that can be interpreted in purely mathematical terms and is thus accessible to the human intellect.
But – and this is the great discovery announced in 1630 – the eternal truths of mathematics, although innate in our minds (“mentibus nostris ingenitae”), are not eternal in themselves or independent of God. They are innate not as such but because God has so willed it – in the sense that in God, as Descartes puts it, “to will, to understand, and to create are the same thing”.19 The latent innatism of the Regulae now seems to have found a higher metaphysical grounding – and with it, a full justification. In other words, the combinatorial structure based on “simple natures” – central in the Regulae – finally gives way to a pyramidal conception of knowledge, with the existence of God placed at the apex as the first truth from which all others derive.
It thus becomes clear why Descartes can claim – on 15 April 1630 – that the existence of God is “more self-evident” than mathematical truths: because the latter depend both logically and ontologically (that is, in their very being, as created entities) on the former, and not the other way around. This can be seen either as a decisive break from the mathematical foundationalism of the Regulae based on the existence of self-evident “simple natures,” or as a coherent radicalisation of that very doctrine, based on the “secret” of order. The search for the ultimate foundation of human knowledge, once pushed to its extreme consequences, leads to a reassessment of the primacy of simple natures and a reassertion of the absolute origin of all truth in the omnipotence of God.
2 The Laws of Nature
As early as the autumn of 1629, Descartes triumphantly announced to Mersenne that he had “decided to explain all the phenomena of nature, that is to say, all of physics”.21 The treatise he began to compose during that period would occupy him for almost four years and would bear an ambitious title, The World, followed by a more modest – but only apparently so – subtitle: or Treatise on Light. Indeed, Descartes considered the question of light to have a privileged status in the new science: years later, he would state that his entire physics depended on the simple analysis of light in terms of matter and motion.22 The initial plan announced a brief text, “to be read in an evening after dinner”.23 In the end, however, the text would expand significantly, eventually including an extensive treatment of the human body, which would be published separately and posthumously under the title L’Homme (Treatise on Man).24 Descartes believed he would complete the entire work at the beginning of 1633. He promised it twice to Mersenne,25 but things turned out differently, and The World, like the Regulae, remained unfinished and unpublished during Descartes’s
The World opens – somewhat unexpectedly – not on a scientific scene but on an epistemological issue: that of the relation between “our sensations and the things that produce them,” which is the subject of the first chapter.27 In fact, the preliminary to the question of the nature of light is the manner in which we apprehend it. Here, the inversion between subject and object of knowledge, advocated at the beginning of the Regulae, clearly surfaces: even to know the external world, one must begin by examining human cognitive faculties (the same line of reasoning will apply to God in the Meditations). However, compared to the Regulae, Descartes places much more emphasis on the dissimilarity between our sensations and the objects themselves: the complex mediation of “figures” traced in the imagination – preserving a certain analogy between the action of bodies on the sense organs and the corresponding modification of corporeal imagination – now recedes into the background.28
The distinction between the qualitative characteristics of bodies perceived by human senses (colours, tastes, smells, sounds and tactile sensations) and their quantitative and measurable characteristics (shape, size, motion, reciprocal position) constitutes a dogma of all forms of mechanism. Descartes adopts it in The World, reconnecting with the major representatives of the scientific revolution, all of whom opposed the scholastic doctrine of “sensible species”, according to which objects send representations of themselves to our sensory apparatus, which is intrinsically capable of receiving them. As Galileo had written since 1623 in The Assayer (Il saggiatore), the sensation of tickling is not a property of the feather nor of the hand, but of the mind of the person who experiences it – and this, he asserted, holds for all sensations.29 In The World, Descartes takes the same example to underline how our perceptions differ from the physical events that cause them: “the ideas of tickling and pain, which are formed in our thought on the occasion of contact with external
The mechanistic interpretation of the perceptual process leads directly, in the following chapters of The World, to the question of what bodies are in themselves. Descartes’s position on this matter is clear: bodies are devoid of non-quantifiable properties; in them, there are neither “real qualities” (such as heat and cold, humidity and dryness), nor “substantial forms” capable of organizing raw matter.32 A declaration thus emerges that sounds like a definition of mechanism: “all the forms of inanimate bodies can be explained without the need to suppose in the matter of the bodies themselves anything other than motion, size, shape, and the arrangement of parts”.33 But the mechanism inherited from Beeckman has now been developed in an original direction. For Descartes, matter is identified with spatial extension. Extension is “that which is most simple and easiest to know among inanimate creatures”34 and is the only characteristic inseparable from matter: one can think of a body without colour or taste, but not without extension. Compared to the Regulae, one can note on the one hand a continuity (the application of the epistemological criterion of simplicity/ease), but on the other hand, an undeniable innovation: extension is now considered as the essence of bodies and is no longer merely a “simple nature” which, united with others, allows us to know them.35 The equivalence thus achieved between matter and extension – a cornerstone
As for the differences between various parts of matter, these are explained solely on the basis of motion: a “solid” body is such only because it is made up of an aggregate of particles possessing the same common motion but which remain at relative rest with respect to one another.39 The so-called “elements” of scholastic physics (water, air, earth, fire) are thus nothing more than names for different configurations of the same identical matter.40 Extremely important in Cartesian physics, “subtle matter” (or “first element”), spread everywhere in the cosmos, is composed of minute particles in whirling motion, capable of filling every interstice between parts of other bodies and of initiating motion everywhere in nature. The other elements are characterized by aggregations of denser matter and possess less motion (as in the case of the “second element,” corresponding to air), or, as in the case of solid bodies, at mutual rest (this is the “third element,” corresponding to earth).41
This matter-extension is conceived in The World as dependent on God at every instant, for its existence and for all its modifications. As already during his partnership with Beeckman,42 but this time explicitly, Descartes borrows from scholastic theology the principle of “continuous creation”: at every moment, God recreates the world, which, by itself, lacks the strength to persist in being and therefore needs the continual creative support of the divine Being. Thus, there is not, nor can there be, any “Nature” endowed with a power of its own, independent of God’s action, and when one speaks of nature one
Persistence of states of motion and rest. A body in motion will continue to move uniformly until it encounters obstacles (a principle already adopted by Descartes around 1618–19, following Beeckman, but here derived as a particular case of the more general principle according to which “every part of matter […] persists in the same state until the collision with others forces it to change” – whereby rest and motion are substantially equivalent states).
Conservation of the quantity of motion. Every body that strikes another transmits to it a quantity of motion identical to that which it itself loses: the quantity of motion in the universe is therefore constant.
Tendency toward rectilinear motion. Bodies have a natural tendency (or “inclination”) towards rectilinear motion, even though, given that a vacuum is impossible, the actual motion of bodies will always be circular, due to the obstacle that other bodies constitute to the movement of individual parts of matter.
The first rule, combined with the third, essentially corresponds to what, little more than half a century later, was to be Newton’s “law of inertia” (and the law of all modern physics to this day); the second posits a conservation principle that is more precisely developed in Newton’s law of action and reaction. But beyond the strictly scientific differences – which will be capital – what opposes Descartes to Newton is precisely his attempt to constitute a deductive physics, of which the founding principles are theologically guaranteed and in which one can arrive at a wholly demonstrative knowledge of nature: “whoever knows how to examine sufficiently the consequences of such [mathematical] truths and of our rules [the laws of physics] […] can have a priori demonstrations of all that may be produced in this new world”.44 Even the tendency towards rectilinear motion depends, for Descartes, on an a priori theological assumption: rectilinear motion is the only conceivable “simple” motion, determinable in a single instant, that is, independently of time; any other motion would require a temporal duration to be completely determined and would therefore be incompatible with the essence of God.45 Newton, instead, would
3 The Fable of the World
From a certain point of view, Descartes’s physics is far more “modern” than Newton’s. For Newton, the universe is still and always will be the theatre of God’s creation and providential power: God is an infinitely wise being, who has harmoniously arranged the planets and who, in His provident wisdom, maintains the cosmic equilibrium. For Descartes, instead, the universe is simply the result of the laws of nature, without the need for local divine interventions beyond the initial creative impulse that reiterates itself at every instant of time. Indeed, to the three laws, or rules, of The World, Descartes entrusts not only the task of fully explaining observable phenomena on earth, renouncing all occult forces, cosmic sympathies or antipathies, real qualities or substantial forms, but also the explanation of the origin of the entire universe, and in particular of the solar system. This latter passage is especially bold and requires an appropriate rhetorical strategy. It is thus that the (potential) reader of the scientific treatise suddenly finds himself catapulted into a “fable,” which Descartes begins to recount as early as chapter 6 of The World.
It is, of course, offered as a “fable” mostly for prudential reasons: Descartes has to reassure professors and theologians of every confession that the concern here is not the true world, created by the God of Scripture in the six days of Genesis, but a fantastic world, which Descartes ironically places in the “imaginary spaces” of scholastic physics.46 It is, moreover, an expedient historically determined by the Catholic Church’s attitude to Copernicanism. At least until Galileo’s trial, the church allowed Copernicanism to be upheld as a pure “hypothesis,” and Descartes’s “fable” could obviously pass for something similar, at least on a superficial reading. However, an attentive reader would have no difficulty in realizing that there is in fact nothing hypothetical at all in Cartesian cosmogony: the world in which the fable takes place is a world governed solely by the necessary laws of mechanics, where no miracles occur and everything depends on the motion of parts of matter. At the end of the
Descartes’s basic intuition consists in the idea that the entire universe is organised by the composition of simple inertial motions. The quantity of motion in the universe remains constant, according to the second “rule” enunciated in The World, but the aggregations among the various bodies and particles change. It sufficed therefore that God, in the beginning, create matter without giving it any particular order. The initial state of the universe was a primordial chaos in which material particles acquired different configurations according to their motion, which is assumed to have been heterogeneously distributed (“let us suppose that God, at the beginning, introduced among the parts of matter all sorts of differences”).48 Since no void existed in creation, every particle collided with others, losing and transferring motion proportionally. Unable to move freely, and thus rectilinearly, the particles of matter immediately assumed a circular motion, which gave rise to vortices of matter. Within these vortices, the centripetal and centrifugal forces determined by motion and by the interaction among bodies engendered respectively the accumulation at the centre of the vortex of particles of the (very fine and highly agitated) first element and the formation of large fluid masses of matter of the second element rotating around the centre, within which are transported conglomerates of solid matter of the third element. The solar system, for Descartes, is nothing but one of these vortices, with the sun at its centre, composed of subtle matter and source of light, and around it the planets, including the Earth, composed of solid matter of the third element, in constant orbital motion.49
For God has established these laws in such a marvellous way that even if we suppose that He creates nothing more than what I have said, and even if He does not impose any order or proportion on it but makes it of the most confused and muddled chaos that any of the poets could describe, the laws of nature are sufficient to cause the parts of this chaos to disentangle themselves and arrange themselves in such a good order that they will have the form of a most perfect world, a world in which one will be able to see not only light, but all the other things as well, both general and particular, that appear in the actual world.51
There is something epic in Descartes’s expressions when he tells his correspondents that he is working on the “fable” of The World. It is as though he were living in a sort of cosmogonic delirium: “I am now set on untangling the chaos to bring out the light from it,” he writes to Mersenne in December 1630.52 And a few months later, to Guez de Balzac, he declares that, without realising it, he
In Holland, where minds were on other things – and above all on commercial profit – Descartes felt he had become so much of a philosopher “that I despise most of the things that are ordinarily valued, and I value other things to which we do not normally attribute much importance.”55 But the temptation of isolation, of estrangement, was always present. And there was no better isolation than that experienced in the midst of a crowd of men busy with their own business: “I take a walk every day amid the bustle of a large crowd, with as much freedom and repose as you would have in your garden paths, and I pay no more attention to the people I see there than I would to the trees in your forests or the animals grazing there. The noise of their commotions no more interrupts my reveries than would the sound of a stream. If sometimes I reflect upon their actions, I derive the same pleasure from it as you get when you see the peasants cultivating your fields; for I can see that all their work serves to enhance the beauty of my residence and to cause me not to be lacking in anything.”56
This is the dream of “complete freedom” that Descartes cultivated in Amsterdam at the beginning of the 1630s.57 A dream destined to be broken soon, despite all the caution maintained throughout the pages of The World.
4 Back to Reality: the Galileo Affair
When working on the World, Descartes knew that he was dealing with a dangerous text, in various respects. At first, he was concerned above all by the
At the end of that same year, Descartes asked Mersenne for news about Galileo’s theories on the tides: perhaps he also wanted to know more about the Dialogue Concerning the Two Chief World Systems, recently published and already censored, but he did not dare ask explicitly. In the meantime, he busied himself with anatomical studies, necessary to complete the part of The World devoted to the human body.64 The next surviving letter to Mersenne dates from the summer of 1633: The World was still unfinished, but Descartes was hoping to send it to him by the end of the year.65
With Galileo, Descartes saw his World itself put on trial and banned: “all the things I explained in my treatise, which included that opinion about the motion of the earth, were so completely dependent on one another, that the knowledge that one of them is false is sufficient for the recognition that all the reasons I made use of are worthless. And although I thought they were supported by very certain and very [self-]evident demonstrations, nevertheless I would not for anything in the world maintain them against the authority of the Church.”68 The desire to flee returned forcefully, and he even let slip an Ovidian motto popular among the libertines of his time: “the desire I have to live in peace and to continue the life I embarked on, taking as my motto: he lives well who hides well (Bene vixit, bene qui latuit), means that I am happy to be freed from the fear I had of acquiring, by means of my writing, more knowledge than I desire, rather than angry at having lost the time and the trouble I used in composing it” (ibid.).
Perhaps it was also, in part, a pretext, albeit a well-chosen and effective one. Descartes asked Mersenne “a year’s delay to revise and polish”, hoping that the condemnation by the Inquisition might not be rigidly enforced. He was soon to discover that the position of the Church was in fact very severe: the prohibition of Copernicanism now applied even in cases where it was proposed “hypothetically,” as had initially been permitted (and this rendered the device of the fable equally useless).69 Meanwhile, he continued to devote himself to research in physics, while metaphysics is almost absent from his correspondence until 1637. What is certain is that there was a setback after the initial enthusiasm of the early months in Holland – an enthusiasm rekindled by the letters to Mersenne in the spring of 1630. But after that date, Descartes, despite having
Already at this point, a specific unresolved conflict can be discerned between the two opposing poles of Cartesian reflection on the foundation of human knowledge: a “humanistic” pole, which had emerged clearly in the Regulae (science is founded on the natural intuition of certain basic and indubitable notions, and all knowledge is founded on the combination of those notions), and a “theocentric” pole, which had manifested itself above all in the letters to Mersenne in the spring of 1630 (science is founded on the absolute power of a God who is not subject to any order, but is the free cause of the essence and existence of things). In the mature formulation of his metaphysics – namely, in the Meditations – Descartes would attempt a mediation between these two poles, without abandoning their specific traits but without evoking their most radical aspects. This would involve a substantial sacrifice of his two most original – and most extreme – positions of the years 1628–1633: the theory of simple natures and the theory of the divine
In 1630, Descartes had proposed his theory of eternal truths with great enthusiasm to Mersenne. He had even ordered him to make it known everywhere: “Do not hesitate, I beg of you, to avow and to proclaim everywhere, that it is God who established these laws in nature, as a King establishes laws in his Kingdom”.71 But it brought with it some problems which were not insignificant. Some of them were raised by Descartes himself: if truths depend on God’s will, could God not change them Himself? But God is immutable, he would immediately respond – thus appealing to the same attribute that underpinned the laws of physics.72 Other problems were less apparent, but far more insidious. With the thesis of the divine creation of eternal truths, Descartes came to maintain that human knowledge does indeed reach the necessary truth of certain propositions – and in particular of mathematical truths – but also that such necessity depends on a free and contingent act of God. With this, the entire preceding Christian theological tradition is overturned (as well as the position of the two great inspirers of the scientific revolution: Galileo and Kepler): to the reassuring absolute necessity of truths in the Platonic-Augustinian tradition, to their being rooted in the divine intellect itself – in which man could, in some way, participate – Descartes would oppose a sharp rupture between man and God, which he would have to try to make up for by means of an adequate rational theology. But how can God be known with certainty after all ties have been severed between the creature and his Creator? Has God truly given man simply a cognitive code that appears eternal and uncreated, but which is in reality dependent on His free will? And is this God a God who wishes to be known – or is He rather an unattainable “hidden God”?
It is therefore not all that surprising that, in the end, the very prudent Descartes never spontaneously presented his theory of eternal truths in a public writing: he did so only when prompted by others, and only some ten years after its first elaboration – that is, after the letters to Mersenne in 1630.73 It is as if the creation of eternal truths never quite managed to become an integral part of Cartesianism. And that is so from the very beginning. Not only does the theory not appear in the published works in which Descartes presents his metaphysics (not, therefore, in Part Four of the Discourse on the Method, nor in the
But during those two weeks – or afterwards – something must have happened, because in The World as it has come down to us, “eternal truths,” that is, mathematical truths, are indeed mentioned, but only in order to indicate that they are innate in the human mind, with no allusion at all to the fact that God himself freely creates such truths – and indeed stating that they would be valid in every possible world.76 The latter assertion would lead a reader unaware of Descartes’s real position to adopt the theory exactly opposite to the one he had expressed in his private correspondence with Mersenne. From the very beginning, then, despite his initial enthusiasm, Descartes considered the theory of creation of truths to be a non-essential element of his system: he did not include it in his physics, just as he would not include it later in his metaphysics.
Almost all interpreters of Descartes have wondered about this embarrassed and embarrassing silence. Prudence or speculative uncertainty? Duplicity or masterly avoidance? Or, possibly, simply fear of being “too free on such lofty matters”?77 Did Descartes perhaps entertain two metaphysics – one private and one public? Is the thesis of the creation of eternal truths a marginal curiosity, albeit a persistent one, or does it constitute a subterranean undercurrent throughout the Cartesian system, of which it is the secret key (or rather, its Achilles heel)? In the Regulae, Descartes had maintained that demonstrations follow an irreversible direction, and that the truth of God’s existence follows from each man’s awareness of his own existence. In 1630, on the other hand,
AT X, 431 (Rule XIII).
Descartes to Mersenne, 15 April 1630 (AT I, 137 ff.; CC I, 57). For a different hypothesis on Descartes’s abandoning the Regulae, see Stephen Gaukroger, Descartes: An Intellectual Biography, Oxford, OUP, 1995, pp. 178–181.
Descartes to Mersenne, 15 April 1630 (AT I, 137 ff.; CC I, 57).
Descartes to Gibieuf, 18 July 1629 (AT I, 17–18; CC I, 16): “I [am about to] finish a little treatise I am starting, which I would not have mentioned until it was done, except that I was afraid the length of time it needed would make you forget your promise to correct it and add some finishing touches”.
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60): “this is the matter I studied above all others, and in which, by the grace of God, I have been satisfied to some extent”.
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60): “The first nine months I was in this country I worked at nothing else, and I believe you already heard me say I had planned to put something of this in writing”.
Descartes to Mersenne, 25 November 1630 (AT I, 182; CC I, 74). Descartes possibly refers to La Mothe Le Vayer’s Dialogues, published in 1630 – but see Alain Mothu’s discussion of this point: “Orasius Tubero et le ‘méchant livre’ de Descartes”, La Lettre clandestine, 4 (1995), pp. 525–538. See also Edouard Mehl, “Le méchant livre de 1630”, Libertinage et philosophie au XVIIe siècle, 1 (1996), pp. 53–67.
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60). The same statement is to be found in Descartes’s letters to Mersenne of 25 November 1630 and April 1637 (AT I, 182, 350–1; CC I, 74, 152).
Descartes to Gibieuf, 18 July 1629 (AT I, 18; CC I, 16): “for I do not expect to finish it within two or three years, and maybe after that I will decide to burn it, or at least not to let it escape my hands or those of my friends without it being well considered, for if I am not clever enough to do something good, at least I will try to be wise enough not to publish my imperfections”.
Descartes to Mersenne, late May or early June 1630 (AT I, 149–50; CC I, 63).
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60 – my italics).
A synoptic table of all Descartes’s texts on the creation of eternal truths can be found in Marion, Sur la théologie blanche de Descartes, cit., pp. 270–1.
Among the possible sources, however, one could mention some passages of Montaigne (Essais, II, 12, ed. Villey, p. 527 ff.) as reported by Edwin M. Curley, Descartes against the Skeptics, Harvard Univ. Press, 1978, pp. 38–40. As for Descartes’s followers on this point, almost all minor French and Dutch thinkers, see Geneviève Rodis-Lewis, Idées et vérités éternelles chez Descartes et ses successeurs, Paris, Vrin, 1985; Emanuela Scribano, Da Descartes a Spinoza. Percorsi della teologia razionali nel Seicento, Milan, F. Angeli, 1988.
Descartes to Mersenne, 6 May 1630 (AT I, 149–50; CC I, 62).
Descartes to Beeckman, 17 October 1630 (AT I, 165; CC I, 69). But on this last point, another echo of Montaigne, see also Descartes to Heny More, 2 May 1649 (AT V, 273).
F. Suárez, Disputationes metaphysicae, XXXI, XII, § 38–47, and in particular § 45: “si per impossible nulla esset talis causa [i.e. God], nihilominus illa enuntiatio [“every animal is sensitive”] vera esset”.
Descartes to Mersenne, late May or early June 1630 (AT I, 151–2; CC I, 62–3).
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60).
Descartes to Mersenne, 27 May 1630 (AT I, 151–2; CC I, 62–3).
Descartes to Mersenne, 15 April 1630 (AT I, 144; CC I, 60).
Descartes to Mersenne, 13 November 1629 (AT I, 70; CC I, 35).
See Descartes to Mersenne, 25 November 1630 and 23 December 1630 (AT I, 179, 194; CC I, 72–3, 77–8); Descartes to Vatier, 22 February 1638 (AT I, 562–3; CC I, 232); Principles of Philosophy, Part 4, § 206.
Descartes to Mersenne, 15 April 1630 (AT I, 137–8; CC I, 60).
On Descartes’s Treatise on Man see below, chap. 3, pp. 74–82.
Descartes to Mersenne, 15 April 1630 and 25 November 1630 (AT I, 137–8, 179; CC I, 57, 73).
Le Monde de Mr. Descartes ou le traité de la lumière, et des autres principaux objets des Sens, avec un Discours du Mouvement Local, et un autre des Fièvres, composez selon les principes du mème auteur, Paris, Th. Girad, 1664.
The World, AT XI, 3; CSM I, 81.
For further developments of this explanatory model in Descartes’s Dioptrics (1637), see Elisa Angelini, Le idee e le cose, pp. 74–87 (and cf. p. 222 ff.).
G. Galilei, The Assayer: “the animated body […] feels different affections according to the different parts [where] it is touched; and being touched […] it feels, in addition to the common touch, another affection, to which we have given a particular name, calling it tickling: which affection is entirely ours, and not at all of the hand” (Galileo Galilei, Opere, vol. VI, p. 348).
AT XI, 5–6. On the various meanings of “idea” in Descartes see below, p. 104.
AT XI, 4–6.
David van Goorle (or Gorlæus, 1591–1612) and Sébastien Basson (around 1580-after 1625) had already declared themselves opposed to these notions before Descartes: the first, Descartes says he has never read (AT VII, 586), while the second is mentioned among the “novatores” in the letter to Beeckman of 17 October 1630 (AT I, 158; CC I, 65).
AT XI, 27.
AT XI, 36.
Ibid.: extension is not an “accident”, that is, a simple quality of matter, but “its true form and essence”. On the Regulae, see above, p. 31.
AT XI, 12.
AT XI, 18.
AT XI, 9 (the same example returns in the Dioptrics, AT VI, 84).
AT XI, 14–6.
AT XI, 23 ff.
Ibid.
See above, p. 11–12.
AT XI, 43.
AT XI, 47.
AT XI, 43–44. See Geoffrey Gorham, “The Metaphysical Roots of Cartesian Physics: The Law of Rectilinear Motion”, Perspectives on Science 13/4 (2005), pp. 431–451.
Cf. The World, chap. 6 (AT XI, 30; CSM I, 90). In medieval philosophy, the doctrine of “imaginary spaces” had been developed by thinkers such as Oresme and Bradwardine as a way to conceptualise the existence of space beyond the known universe, even space not yet populated by physical bodies.
Writing to Mersenne on 13 November 1629, Descartes declared he had found “how to expound all my thoughts in a way that some will find satisfying and others will not have the occasion to contradict” (AT I, 70; CC I, 35).
The World, chap. 8 (AT XI, 50).
The World, chap. 8–10 (AT XI, 48–72). The three “elements” of Descartes’s physics obviously do not differ essentially from each other: the only difference between them depends on their respective quantity of motion.
For a later reappearance of this (potentially atheistic) image of God, see infra, p. 220, on Descartes’s letter to Henry More (1649).
The World, chap. 6 (AT XI, 35; CSM I, 91).
Descartes to Mersenne, 23 December 1630 (AT I, 194; CC I, 78).
Descartes to Guez de Balzac, 15 April 1631 (AT I, 199; CC I, 82).
Descartes to Vatier, 22 February 1638 (AT I, 561; CC I, 231).
Descartes to Guez de Balzac, 15 April 1631 (AT I, 198–9; CC I, 82).
Descartes to Guez de Balzac, 5 May 1631 (AT I, 203; CC I, 84).
Ibid.: “in what other country can one enjoy such complete freedom, where one can sleep with less restlessness” (AT I, 204; CC I, 84).
Descartes to Mersenne, 18 December 1629 (AT I, 86; CC I, 40).
Descartes to Mersenne, 18 December 1629 (AT I, 85–6, CC I, 40).
The World, chap. 6 (AT XI, 33). On the difference between “indefinite” and “infinite”, see also Principles of Philosophy, 1st Pt., §26–27.
Descartes to Mersenne, 23 December 1630 (AT I, 194; CC I, 78).
Descartes to Mersenne, 5 April 1632 (AT I, 242; CC I, 95) and 3 May 1632 (AT I, 248; CC I, 97).
Descartes to Mersenne, summer 1632 (AT I, 258; CC I, 100).
Descartes to Mersenne, November or December 1632 (AT I, 261; CC I, 100–101).
Descartes to Mersenne, 22 July 1633 (AT I, 268; CC I, 106).
The more strictly physical part of The World is lacking two chapters (16 and 17), while the part on man does not include the analysis of the union between mind and body, promised at the beginning of the text (AT XI, 120).
Descartes to Mersenne, late November 1633 (AT I, 270; CC I, 107).
Descartes to Mersenne [Late February 1634] (AT I, 286; CC I, 111).
Descartes to Mersenne, late November 1633, February 1634, [Late February 1634], and 14 August 1634 (AT I, 272, 281–282, 285–288, 305–306; CC I, 107, 110, 111, 118–119).
In The World, the “nature” of movement is designated as “simple and intelligible” (AT XI, 39). See also, in the 1st Meditation, the list of things which are “simpler and more universal” (AT VII, 20; CSM II, 13–14); and cf. Descartes to Mersenne, 16 October 1639 – AT II, 597). In the Principles of Philosophy, 1st part, §10, Descartes speaks of some “very simple notions”, and in a letter to Elizabeth of the Palatinate to which we will return he will speak of some “primitive notions”. However, the only occurrence of the syntagm “simple natures” after 1628 is to be found in the Colloquium with Burman of 1648 (AT V, 160), where, however, Descartes maintains that they depend on the will of God, thus denying their epistemological autonomy. On the fate of the “simple natures” after the Regulae, see the contrasting theses of Jean-Luc Marion, Questions cartésiennes, Paris, Puf, 1991, pp. 75–110 (substantial continuity) and of Gilles Olivo, Descartes et l’essence de la vérité, cit., pp. 273–352 (irreducible epistemological break).
Descartes to Mersenne, 15 April 1630 (AT I, 145–6; CC I, 60).
Descartes to Mersenne, 15 April 1630 (AT I, 145–6; CC I, 60). On this point, see S. Landucci, La teodicea nell’età cartesiana, Napoli, Bibliopolis, 1986, pp. 127–93.
See Descartes’s 5th and 6th Replies to Mersenne’s and Gassendi’s objections (AT VII, 380, 431–6).
Some vague allusions, identifiable only by those who are familiar with Descartes’s thesis, can possibly be found in the Discourse on the Method and in the Principles: see G. Rodis-Lewis, L’Œuvre de Descartes, cit., I, pp. 133–135. See also infra, p. 117, n. 89–90.
Descartes to Mersenne, 15 April 1630 (AT I, 145; CC I, 60).
AT XI, 47. On the possibility that The World underwent a revision after 1633, see R. Love, “Revisions of Descartes’s Matter Theory in Le Monde”, The British Journal for the History of Science, 1975, pp. 127–137.
Descartes to Mersenne, 6 May 1630 (AT I, 149; CC I, 62): “I do not wish to meddle in Theology; I am even afraid you may judge that my philosophy is becoming too free, since it dares to speak out on such lofty matters”.
Descartes to Mersenne, 6 May 1630 (AT I, 149; CC I, 62).
Descartes to Mersenne, 6 May 1630 (AT I, 149; CC I, 62).