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‘Descartes’s One Rule of Logic’: Gassendi’s Critique of the Doctrine of Clear and Distinct Perception

2005; Taylor & Francis; Volume: 13; Issue: 1 Linguagem: Inglês

10.1080/0960878042000317582

1469-3526

Antonia LoLordo,

Historical Philosophy and Science

Click to increase image sizeClick to decrease image size Notes 1 Pierre Gassendi, Opera Omnia I 65b; Georg Olms, 1964. All references to Gassendi's works are to volume, page, and column in his Opera Omnia. Volumes I and II are the Syntagma Philosophicum and references to volume III are to the Disquisitio Metaphysica. Translations are my own but I have benefited greatly from consulting the CSM translation of the Objections. 2 For example, Franco Burgersdijck, Robert Sanderson, and Zabarella append histories of logic to their expositions. See also E. J. Ashworth (Language and Logic in the Post-Medieval Period, D. Reidel, 1974) and Gabriel Nuchelmans (in the Cambridge History of Seventeenth-Century Philosophy, ed. Garber and Ayers, 1998). 3 After Gassendi's death, Sorbiere (in a letter of 1656) asked Hobbes to write the 'Hobbes' Logic' chapter that Gassendi had planned to write before he died. Hobbes declined. 4 For instance, Aquinas and his followers organized logic according to the three mental operations: simple apprehension (forming terms); composition and division (forming propositions); and reasoning (forming arguments). Some writers thus organized logic books in three parts, terms, propositions, and reasoning (as well, perhaps, as method as the fourth part). Others, like Gassendi, chose the names of the mental operations. See Ashworth (op. cit.), who denies that this method of organization makes logic psychologistic in the strong sense of implying that the study of logic simply is the study of the mental operations. 5 See Stephen Gaukroger (Cartesian Logic: An Essay on Descartes's Conception of Inference, Clarendon Press, 1989) and Gary Hatfield ('The Workings of the Intellect: Mind and Psychology', in Easton (ed.), Logic and the Workings of the Mind: The Logic of Ideas and Faculty Psychology in Early Modern Philosophy. North American Kant Society Studies in Philosophy, 1997) as well as Nuchelmans. 6 The view that logic is an art was the standard humanist view, and was also held by diverse writers like Burgersdijck and Zabarella. Cf. Nuchelmans. 7 In these passages Gassendi reads Descartes as thinking that the acquisition of knowledge requires only the intellect, thus discounting the role of sense-based knowledge in Descartes's programme. Whether this is a product of genuine misunderstanding or is an exaggeration done for rhetorical purposes is difficult to tell. Gassendi certainly knew of and respected Descartes's empirical scientific work, having read the Discourse, Optics, Geometry, and Meteorology, although I know of no evidence suggesting he took it as particularly closely related to the project of the Meditations. 8 we suffer so much loss of hope with you, so great a man, with so much expected from … can it happen, that this man, brought up in the study of Mathematics and so well knowing what things are demonstrations, considers and publishes these arguments as demonstrations, which nevertheless cannot elicit assent from us who direct our attention toward them and are well-disposed? Or that he – puffed up with pride from having thought of and discovered some new things in Geometry – considers it possible that he will be equally fortunate in other related matters and especially Metaphysics? (Cf. III 275b) 9 Gassendi is certainly right in that the Meditations present clear and distinct perception as a method of discovery rather than a way of legitimizing claims arrived at on some other basis. It is rather less clear that Descartes himself used clear and distinct perception as a method of discovery. The presentation of it in the Meditations is misleading, as scholarly work on Descartes's observational work has shown. 10 This requires qualification. Gassendi talks as if clear and distinct perceptions are supposed to be true in virtue of exhibiting essences of existing things. On Descartes's view, however, some clear and distinct perceptions (e.g. perception of the thinking I or the common notion whatever thinks exists) have objects which are not essences; others (e.g. perception of mathematical entities) have as their objects essences which need not be instantiated. The first sort becomes important only in disputes about the cogito. I shall bracket out the second sort as much as possible, to keep the focus on clear and distinct perception. Readers interested in an approach from the direction of essences should consult Olivier Bloch (La Philosophie de Gassendi: Nominalisme, máterialisme, et métaphysique, Nijhoff, 1970), Thomas Lennon ('Pandora, Or, Essence and Reference: Gassendi's Nominalist Objection and Descartes's Realist Reply,' in Roger Ariew and Marjorie Grene (eds), Descartes and his Contemporaries, University of Chicago Press, 1995) or Margaret Osler (Divine Will and the Mechanical Philosophy: Gassendi and Descartes on Contingency and Necessity in the Created World, Cambridge, 1995). 11 Descartes denies this by claiming that 'it can never be proved that [such people] clearly and distinctly perceive what they so stubbornly affirm' (AT VII 361). Gassendi does not take this denial seriously: For us, who are men [as opposed to disembodied minds] and who, as is suitable for men, reason from things done [ex effectis], the fact that these men go to meet death for the sake of some opinion appears to be a perspicuous argument that they perceive it clearly and distinctly as the best and the one which should be followed. (III 317a) 12 It is important that Gassendi thinks the same could not be said for what is clearly and distinctly sensed, as he holds that the appearances themselves cannot be false, only judgements made on the basis of the appearances. Nor can appearances conflict with each other, as the information they convey is always relative to the context of perception. This is supposed to provide a basis for a genuine, sensory truth-criterion. 13 For the possibility of those who have not meditated mistaking something else for clarity and distinctness, see e.g. AT VII 35: '… there was something else which I used to assert, and which through habitual belief I thought I perceived clearly, although I did not in fact do so'. 14 All four causes of error listed at Principles I 71–4 pertain either to reversion to preconceived opinions or to paying attention to words rather than things – that is, with lapses in attention or failure to clear the mind of preconceived opinions. So Descartes allows occasional sources of error aside from preconceived opinions of the senses, but, I take it, the contrast between distortions like fatigue and distortions like reliance on the senses is intuitively clear. 15 This may seem in tension with the Principles' definitions of clarity and distinctness: clear perceptions are 'present and accessible to the attentive mind'; distinct perceptions are clear and also 'so sharply separated from all other perceptions' that they contain within themselves only what is clear. But note that the explanation of being 'present and accessible to the attentive mind' – i.e. that presentness operates as it does in the case of vision, where we see something clearly 'when it is present to the eye's gaze and stimulates it with a sufficient degree of strength and accessibility' – would not help anyone understand clarity and distinctness from the outside. Here, again, Descartes points to an example of clear and distinct perception and intends the reader, who has similar God-given faculties, to generalise. 16 See Hatfield, 'The Senses and the Fleshless Eye: The Meditations as Cognitive Exercises' (in Stephen Voss (ed.) Essays on the Philosophy and Science of Rene Descartes, Oxford, 1993). 17 For it is left open at this point that the clarity and distinctness rule, though compelling, may be false because his nature might be such that he is systematically deceived. This worry bears on the metaphysical question, however, and not the methodological question: it is no longer concerned with picking out a stable, consistent, and commonly-shared set of clear and distinct perceptions but rather with determining that the set provides the basis for knowledge of the world. 18 Note that this does not fully explain why someone should not worry that his own clear and distinct perceptions, although consistent as a set, are inconsistent with those of other people. However, both Descartes and Gassendi seem happy to assume that the basic cognitive faculties operate in the same way for all people, so that if what's clearly and distinctly perceived is a product of the basic operations of the intellect alone, clear and distinct perception should be the same for all people. 19 Gassendi tends to equate innate ideas with purely intellectual ideas. However, innateness does not do any work of its own in Gassendi's argument; it just functions as a corollary of the existence of peculiarly intellectual ideas (and the consequent postulation of the intellect as a distinct faculty not dependent for its operation on sense or imagination). The reader may substitute 'intellectual' for 'innate' in reading Gassendi's texts if she wishes. 20 For Descartes, an idea can be either term-like or propositional in form, and a judgement is the giving or denying of assent to something presented in idea. For Gassendi, ideas must always be terms, and judgments are the joining of two ideas by is or is not. (This leaves him with a problem in distinguishing between believing a proposition and entertaining it.) On his theory of ideas, judgements are wholly determined by the ideas possessed, so that withholding or granting assent to a propositional complex is never an act of will but is fully determined by the intellect. Hence, for Gassendi, the contents of judgement are determined by the contents of ideas, so that he is unwilling to allow Descartes that judgements can be doubted while ideas remain unchanged. 21 We abstract the idea of substance, such as the substance of the wax, from the idea of body (etc.) which is in turn arrived at by abstraction from the idea of rocks, trees, dogs, etc. These last ideas are arrived at by grouping together particular sense perceptions on the basis of similarity. The chiliagon case is more complicated, and for Gassendi mathematical ideas are a special case since – unlike the ideas of other 'theoretical entities' – they do not carry existence claims with them. 22 When things do not always appear the same – when we have several different ideas of, i.e. caused by, the same thing – the judgements can be changed. Consider the idea of the size of the sun: through sight, we obtain an idea of the sun as something very small; but the idea of the sun modified by the mind on the basis of the empirical observations that distant objects appear smaller than they are and that the sun is distant, is an idea of something much larger. In learning astronomy, our idea of the size of the sun changes; the ideas which determine judgement are not exclusively basic sensory ideas. See III 321a ff. 23 This is over-simplified. All judgement falls under the scope of the will and hence is voluntary in one sense. However, clear and distinct perception is irresistible – 'Admittedly my nature is such that so long as I perceive something very clearly and distinctly, I cannot but believe it to be true' (AT VII 69) – and hence involuntary in another sense. This complication can be ignored since the 'preconceived opinions' which the method of doubt applies to are not perceived clearly and distinctly. 24 The argument about the intellectual and imaginative conceptions of the chiliagon is the most obvious other possibility: but this is given too late in the dialectic to help. 25 I have in mind here primarily epistemologically-minded figures like Arnauld and Malebranche. Those more oriented towards natural philosophy, such as Regius, tended to be interested in a method of discovery and rejected clear and distinct perception as inappropriate for that purpose. 26 Arnauld and Nicole, Logic or the Art of Thinking, pp. 247–8 (trans. by Jill Buroker, Cambridge, 1996). See Lennon (Ibid) for a different but (I think) compatible way of relating this passage to the Gassendi-Descartes debate. 27 I would like to thank Martha Bolton, Raffaella De Rosa, Peter Klein, Paul Lodge and Jorge Secada for helpful comments on previous versions of this paper. Some research was generously supported by a joint fellowship from Caltech and the Huntington Library.