Scepticism and the Early Descartes

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Notes

¹This paper is indebted to the careful criticism of Donald Rutherford, Alan Nelson, Jonathan Cohen, an anonymous referee, members of the History of Philosophy Roundtable at the University of California, San Diego, participants at the American Philosophical Association, Pacific Division Meeting, 2003, particularly commentator Gary Steiner, as well as participants at the Midwest Seminar in Early Modern Philosophy, Lecce, Italy, 2002.

²I will use the following abbreviations: CSM/CSMK = The Philosophical Writings of Descartes, by John Cottingham, Robert Stoothoff, and Dugald Murdoch (and volume 3) Anthony Kenny (trans.) (Cambridge: Cambridge University Press, 1984, 1985, 1991). Includes marginal pagination to Oeuvres de Descartes, Charles Adam and Paul Tannery (eds) (Paris: J. Vrin, 1964–74). La verité = Marin Mersenne, La verité des sciences, contre les sceptiques ou pyrrhoniens (Paris: 1625). Translations from La verité are my own. ST = Saint Thomas Aquinas, Summa Theologica, cited by part, question and article. Translations are from Vernon J. Bourke, The Pocket Aquinas (New York: Simon & Schuster, 1960).

³The structure of the Regulae is deceptively complex. According to Rules Eight and Twelve, the Regulae are to be divided into three parts, each containing twelve rules with commentaries. This scheme was, however, a late addition to the text, appended nearly a decade after Descartes began work on the Regulae. The text was most likely composed in stages over a long stretch of time from 1619 until 1628. The first stage is represented by the second half of Rule Four, referred to as Rule 4b. It dates sometime between Descartes's April letter to Beeckman and the dream of 10 November. The dream led to a burst of productivity during which Descartes completed the first eleven rules with the exception of 4b and parts of Rule Eight. It is possible Descartes regarded the work as completed at this point, since his suggestion for a tripartite division had not yet been added. Descartes neglected the text for some time until 1626. During the Paris years, from 1626 to 1628, he returned to the text, adding Rules Twelve to Twenty-one and making significant additions to Rule Eight. It is only in the final stratum that Descartes proposes the tripartite division of the text. Thus, the later additions provide a superficial programmatic which connects the various stages of the work, thereby belying a series of discrete and often divergent accounts. The foregoing discussion of the composition of the Regulae is essentially the thesis of Schuster; see John A. Schuster, Descartes and the Scientific Revolution, 1618–28: An Interpretation (Ph.D. dissertation, Princeton University, 1977) and ‘Descartes's Mathesis Universalis, 1619–1628’, in Descartes: Philosophy, Mathematics and Physics, Stephen Gaukroger (ed.) (Sussex: Harvester Press, 1980) pp. 41–96. Schuster draws on Jean-Paul Weber, La constitution du texte des Regulae (Paris: Societe d'edition d'enseignement superieur, 1958). My account depends only on the broad outlines of this reading: that there are three stages of composition; Rule Twelve was added and Rule Eight reworked in the final stage, written during the Paris years.

⁴See Rule Ten of the Regulae and Part Two of the Discourse.

⁵This metaphor continues to be important in Descartes's mature philosophy, as is evident from the doctrine of clear and distinct perception and the opposition between ‘clarity’ and ‘obscurity’. Descartes explains the similarity between vision and intuition in Rule Nine:

We can best learn how mental intuition is to be employed by comparing it with ordinary vision. If one tries to look at many objects at one glance, one sees none of them distinctly. Likewise, if one is inclined to attend to many things at the same time in a single act of thought, one does so with a confused mind. Yet craftsmen who engage in delicate operations, and are used to fixing their eyes on a single point, acquire through practice the ability to make perfect distinctions between things, however minute and delicate. The same is true of those who never let their thinking be distracted by many different objects at the same time, but always devote their whole attention to the simplest and easiest of matters; they become perspicacious.

(CSM I 33)

⁶It is important to note here that the mature Descartes will not accept these claims so easily.

⁷Descartes uses the term ‘universal science’ to refer to the method in his original title for the Discourse, as recounted to Mersenne in a letter of March 1636 (CSMK 51). This notion of a unified or universal science is central to Descartes's early thinking. It is described in one of his first recorded philosophical writings:

The sciences are at present masked, but if the masks were taken off, they would be revealed in all their beauty. If we could see how the sciences are linked together, we would find them no harder to retain in our minds than the series of numbers.

(CSM I 3)

⁸For biographical information on this time, see Adrien Baillet, La vie de Monsieur Descartes (Paris, 1691; facsimile reproduction Geneva, 1970) and Genèvieve Rodis-Lewis, Descartes: Biographie (Paris: Calmann-Levy, 1995).

⁹See Richard Popkin, The History of Skepticism from Erasmus to Spinoza, chapter 9.

¹⁰Adrien Baillet, La vie de Monsieur Descartes, p. 70. For further discussion of this event, see Popkin, The History of Skepticism from Erasmus to Spinoza, p. 174 and Gaukroger, Descartes: An Intellectual Biography, p. 183.

¹¹He writes ‘this is the first question of all that should be examined by means of the Rules described above’ (CSM I 31).

¹²For a discussion of Mersenne's treatment of scepticism, see Lenoble, Mersenne ou la naissance du mecanisme, pp. 316–25; Peter Dear, Mersenne and the Learning of the Schools (Ithaca: Cornell University Press, 1988) chapter 3; Popkin, The History of Skepticism from Erasmus to Spinoza, chapter 7.

¹³Harcourt Brown, Scientific Organizations in Seventeenth-Century France (New York: Russell & Russell,1934) p. 38, argues that political pressures made Mersenne reluctant to express his views bluntly. Fortunately there is enough philosophical content in La verité to confirm that Mersenne held by 1625 the major theses of his later work: (1) mitigated scepticism; (2) the highest certainty of mathematics; (3) the theory of divine ideas, and (4) the doctrine of the natural light. However, I am often forced to resort to Mersenne's later work for the clearest formulation of the views described in La verité. However, we should not suppose that, because Mersenne was cagey about expressing his views in his written work, they would be unknown to his confidantes, such as Descartes. Nevertheless, the reader should be warned that the position I describe is far more clean and systematic than Mersenne's presentation in 1625.

¹⁴Mersenne is best known for circulating the Meditations, resulting in the Objections and Replies. Descartes also asks Mersenne to circulate a ‘little treatise’ in a letter 18 December 1629 (CSMK 14). This is probably the Meteorology, as indicated by a letter of 8 October 1629 (CSMK 6).

¹⁵Descartes's discussion is contained in Rule Twelve, which is structured by his two-pronged treatment of the question concerning knowledge and its scope: the first part of Rule Twelve offers an account of the cognitive faculties and their function, which aims to reconcile Descartes's emerging mechanism with his earlier claims about cognition. Thus it describes the imagination and the senses in mechanistic terms, offering a position that would reappear, though in a somewhat different form, in Dioptrics; this aspect of Rule Twelve has been discussed in detail elsewhere. See Dennis L. Sepper, Descartes's Imagination: Proportion, Images and the Activity of Thinking (Los Angeles and Berkeley: University of California Press, 1996) and Eric Palmer, ‘Descartes’ Rules and the Workings of the Mind’, in Logic and the Workings of the Mind: the Logic of Ideas and Faculty Psychology in Early Modern Philosophy, Patricia Easton (ed.) (Atascadero: Ridgeview Publishing Company, 1997) pp. 269–82. This paper is interested in the often-neglected second prong of Descartes's investigation into the objects of knowledge: simple natures.

¹⁶In Rule Six, Descartes equates them with ‘absolute things’, the conception of which does not presuppose any other concept. He writes:

We should note that there are very few pure and simple natures which we can intuit straight off and per se (independently of any others) either in our sensory experience or by means of a light innate within us. We should, as I said, attend carefully to the simple natures which can be intuited in this way, for these are the ones which in each series we term simple in the highest degree. As for all other natures, we can apprehend them only by deducing them from those which are simple in the highest degree, either immediately and directly, or by means of two or three or more separate inferences.

(CSM I 22)

¹⁷It should be noted that Descartes was opposed to scholastic-Aristotelianism; he claims ‘the precepts with which dialecticians suppose they govern human reason’ are ‘inimical to our project’ (CSM I 3). Nevertheless, given the pervasiveness of scholastic doctrines, it should not be surprising that Descartes's first stab at an epistemological theory bears a general resemblance to some of them.

¹⁸Descartes would have been familiar with Aquinas from his studies at La Flèche. For an account of the curriculum, see Gaukroger (Descartes: An Intellectual Biography, chapter 2).

¹⁹See Posterior Analytics (72b, 10–15) in Aristotle Selections, Terence Irwin and Gail Fine (trans.) (Indianapolis: Hackett Publishing Company, 1995) as well as Aquinas's commentary to it, discussed in Scott MacDonald, ‘Theory of Knowledge’ in The Cambridge Companion to Aquinas, Norman Kretzmann and Eleonor Stump (ed.) (Cambridge: Cambridge University Press, 1993) p. 169, and John I. Jenkins, Knowledge and Faith in Thomas Aquinas (New York: Cambridge University Press, 1997), chapter 1.

²⁰Aristotle first states that the immediate principle of a syllogism is of two kinds. One is called a postulate [positio]; it is not susceptible of demonstration and that is why it is called immediate. Yet, it is not necessary for the pupil, the person whose role is to be taught in a demonstrative science, to have it, that is, to intuit it mentally or to assent to it. The other kind, however, is what is called an axiom [dignitas], or a maximal proposition. Now, everyone whose function is to be taught must have this sort of proposition in his mind and give assent to it. (Aquinas, Exposition of Aristotle's Posterior Analytics, I Lecture 5. from Vernon J. Bourke, The Pocket Aquinas (New York: Simon & Schuster, 1960) p. 31)

Of course, my discussion of immediate principles concerns only the former – propositions which are accepted as true, but cannot be demonstrated. The latter (axioms) are things accepted as stipulative truths but do not necessarily serve as fundamental principles out of which all scientia falls.

²¹‘For instance, this proposition: all right angles are equal, is in itself self-evident or immediate, because such equality falls within the definition of the right angle’ (Bourke, The Pocket Aquinas, p. 32).

²²For a detailed account of this theory, see Stephen Gaukroger, Cartesian Logic (Oxford: The Clarendon Press, 1989).

²³This is evident, for instance, in Descartes's proof of the law of refraction in the Dioptrics, where he models the behavior of light on the motion of bodies (CSM I 156–64).

²⁴For a nice discussion of this point, see Keith DeRose ‘Solving the Skeptical Paradox’, Philosophical Review, (1995) 104 (11): 1–52.

²⁵This line of argument in Montaigne is documented in Husain Sarkar, Descartes' Cogito: Saved from the Great Shipwreck (Cambridge: Cambridge University Press, 2003) 102–9.

²⁶Michel de Montaigne, The Complete Essays, D. Frame (trans.), (Stanford: Stanford University Press, 1958) p. 132.

²⁷Mersenne's commitment to the theory of divine ideas is also asserted in his famous 1630 correspondence with Descartes concerning the eternal truths. Against Descartes's suggestion that God wills the possible, Mersenne defends the notion that the divine will is constrained to choose the created world from among the divine ideas, which stipulate the possible.

²⁸Mersenne, L'impiete des deists (Paris 1624) 311–12; translation from Dear (Mersenne and the Learning of the Schools).

²⁹It should be noted that Mersenne does not believe divine ideas can be known directly by humans; our knowledge of them, like our knowledge of God is imperfect.

³⁰Mersenne, Questions theologiques, physiques, morales, et mathematiques (Paris 1634) p. 9; translation from Dear (Mersenne and the Learning of the Schools).

³¹Mersenne, Questions theologiques, physiques, morales, et mathematiques, p. 11; translation from Dear (Mersenne and the Learning of the Schools).

³²For instance, he writes:

once he has discovered this mixture, he is in a position to make the bold claim that he has grasped the true nature of the magnet, so far as it is humanly possible to discover it on the basis of given observations.

(CSM I 50)

³³This point is also demonstrated by Descartes's remarks on number games:

since nothing in these activities remains hidden and they are totally adapted to human cognitive capacities, they present us in the most distinct way with innumerable instances of order, each one different from the other, yet all regular. Human discernment consists almost entirely in the proper observance of such order.

(CSM I 35)

³⁴This point is nicely explained in Curley's response to Frankfurt; see Descartes against the Skeptics (Cambridge: Harvard University Press, 1978) p. 110.

³⁵Again, see DeRose 1995.

³⁶Loeb argues for a kind of psychologist reading that argues Descartes is primarily concerned to achieve a set of stable or unshakeable beliefs. See Loeb, ‘The Cartesian Circle’, and Frankfurt, Demons, Dreamers and Madmen (Indianapolis: The Bobbs-Merrill Company, 1970).

³⁷It should be noted, that this interpretation of the Meditations is somewhat controversial. Some argue that the Meditations exempt certain sorts of clear and distinct perceptions from doubt. Nevertheless, the point stands that the scepticism considered in the Meditations is far stronger than that in the Regulae.