LoLordo (2005) ‘Descartes’s One Rule of Logic’: Gassendi’s Critique of the Doctrine of Clear and Distinct Perception.

LoLordo, Antonia (2005). ‘Descartes’s One Rule of Logic’: Gassendi’s Critique of the Doctrine of Clear and Distinct Perception. British Journal for the History of Philosophy 13 (1):51 – 72.

Because he estimates that the way to have true and appropriate cognition of things is not by exploring things through themselves and in themselves, but by the Intellect alone and depending on thoughts alone, to that extent Descartes’s procedure is certainly less appropriate than Bacon’s appeared to be. If there is in the end anything that concerns Logic in all that which follows, it is above all that Principle which the author poses as follows: Everything that I clearly and distinctly perceive is true. (I 90a)

THE MEDITATIONS AS LOGIC

In any case, the early seventeenth-century construal of logic was much broader than ours. Logic tended to include material we would call epistemology, philosophy of science, or psychology.4 That is, it had both descriptive aspects– corresponding to how we actually think– and normative aspects– telling us how to think better.5 This was not thought to imply the disunity of logic, as the normative and descriptive aspects seem to have been thought of as inseparable.

What matters here is that method, like logic in general, fuses psychological and epistemological components. Thus, Gassendi assumes, for the project of the Meditations to succeed, the method has to be useful; it has to be something that would give us the truth (or as close as can reasonably be expected) if used properly, and something that we can actually carry out. Gassendi, as we shall see, denies that we can carry out the method of the Meditations. In fact, he denies that Descartes’s procedure fulfils either criterion. We cannot actually carry out the method, since we cannot doubt all sensory beliefs and thereby end up with a clear and distinct perception of purely intellectual ideas. Nor can we learn the truths of nature by focusing on Descartes’s allegedly clear and distinct ideas.

CLARITY AND DISTINCTNESS

Gassendi denies that Descartes’s meditative method is practicable because he denies that we can isolate a stable, consistent, and commonly held set of clear and distinct perceptions. He begins by noting that clear and distinct perception is supposed to be both introspectible and objectively justificatory:

1. the clarity and distinctness of a perception is something to which the perceiver has immediate, incorrigible introspective access;

2. all clear and distinct perceptions are true– in central cases, true in virtue of exhibiting to the perceiver the essences of things.

Then Gassendi argues that (a) and (b) do not have the necessary connection Descartes requires, in other words, that the link between the experiential property and the truth-linked property cannot be established.

In fact, Gassendi argues, (a) and (b) are incompatible as general rules. For one thing, experience seems to tell us that they are inconsistent, for we recognize that there have been cases when we thought we perceived something clearly and distinctly and later perceived something else incompatible clearly and distinctly.

This is supposed to show that anyone who holds that all clear and distinct perceptions are true must also hold that there can be mistakes about whether a perception is clear and distinct.11 But if this is so– if clarity and distinctness are not a matter of incorrigible, first-person access– then we need a mark for telling which of our persuasive perceptions are actually clear and distinct:

What you should be working on is not so much confirming this rule which makes it so easy for us to take the false for the true, but instead proposing a method to guide us and teach us when we are mistaken and when not, in the cases where we think we clearly and distinctly perceive something. (III 315a)

In response, Descartes points out that clarity and distinctness are features only of the perceptions of people who have freed their minds from the senses, i.e. who have properly followed the method of meditating.¹³ Such people will not be mistaken about what is clearly and distinctly perceived. But since Gassendi has failed to meditate in this way, inconsistencies among his apparently clear and distinct perceptions are irrelevant to Descartes’s project. Gassendi fails to grasp the efficacy of the method because he is still ‘mired in the senses’.

As for the method enabling us to distinguish between the things that we really perceive clearly and those that we merely think we perceive clearly, I believe, as I have already said, that I have been reasonably careful to supply such a method, but I have little confidence that those who spend so little effort on getting rid of their preconceived opinions that they complain that I have not dealt with them in a ‘simple and brief’ statement will arrive at a clear perception of it.
(AT VII 379)

Those who have not abandoned preconceived opinions and freed themselves from the senses cannot perceive clearly and distinctly; but those who have freed their intellects will never disagree about what is clearly and distinctly perceived. Hence clarity and distinctness need no mark beyond the associated compulsion to believe. So, Descartes replies, the method for determining which perceptions are genuinely clear and distinct has already been given:

You say at the end of this section that what we should be working on is not so much a rule to establish the truth as a method for determining whether or not we are deceived when we think we perceive something clearly. This I do not dispute; but I maintain that I carefully provided such a method in the appropriate place, where I first eliminated all preconceived opinions and afterwards listed all my principal ideas, distinguishing those which were clear from those which were obscure or confused. (AT VII 361–2; cf. AT VII 477 & IXb 22–3)

This response initially seems unhelpful. Gassendi asked for a method for distinguishing genuinely clear and distinct perceptions from belief-compelling, but not clear and distinct, acts of the mind. Descartes responds that a method has been given, as follows: eliminate all preconceived opinions, list the principal ideas, and distinguish the clear principal ideas from the obscure or confused principal ideas. One might now ask how the last step is to be carried out– isn’t distinguishing clear principal ideas from obscure ones just a special case of distinguishing the genuinely clear and distinct?

Descartes’s answer, I take it, is yes– but it is a case where error is impossible. For error in seeing what’s perceived clearly and distinctly results from the contagious effect of obscure and confused concepts acquired before the age of reason:

those who do not abandon their preconceived opinions will find it hard to acquire a clear and distinct concept of anything; for it is obvious that the concepts which we had in our childhood were not clear and distinct, and hence, if not set aside, they will affect any other concepts which we acquire later and make them obscure and confused. (AT VII 518)

Once methodological doubt removes such distortion, there is no principled difficulty identifying clear and distinct perceptions.14 There is then no need for any further criterion of clarity and distinctness; it can be defined simply by pointing at examples we have experienced.15 Recall what Descartes says about clear and distinct perception in the Geometrical Appendix to the Second Replies:

I ask my readers to ponder on all the examples that I went through in my Meditations, both of clear and distinct perception, and of obscure and confused perception, and thereby accustom themselves to distinguishing what is clearly known from what is obscure. This is something that it is easier to learn by examples than by rules, and I think that in the Meditations I explained, or at least touched on, all the relevant examples. (AT VII 164)

The examples given in the Meditations are examples that must be experienced by the reader in order to be compelling.16 Descartes asks the reader to follow him in getting herself in a position to, for example, perceive the thinking I clearly and distinctly; we are supposed then to be certain of the existence of that I. Then he points out that the feature of the experience which made the reader certain is what he means by clarity and distinctness (cf. AT VII 162–3).

Gassendi says, in objection to this, that Descartes seems

in reverse order and contrary to the laws of Induction, to infer a universal proposition from the sole observation of a singular proposition, when, from the mere fact that you have observed that the certainty of this proposition I think springs from clear and distinct perception, you infer this conclusion, therefore everything which I perceive clearly and distinctly is true. (III 316a)

Descartes’s response is helpful. He is not, he tells us, inferring a universal proposition from one observed instance. Rather, experiencing that instance makes him notice a general rule already implicitly and inevitably ascribed to, one whose truth-conduciveness he will examine in the worry about the deceiving God.17 The general rule is supposed to gain its initial plausibility not from induction but because of our felt compulsion to follow it.

DESCARTES’S RESPONSE

This response runs together two different claims: a general, anti-skeptical thesis and, less explicitly, an echo of Descartes’s claim about which sorts of ideas are ‘clear and distinct’ and thereby license inference to the nature of things. However, so doing makes the response less than satisfying, since the point of Gassendi’s empiricist objection is precisely that the Cartesian account of which ideas license inferring to the nature of things can be challenged without falling into skepticism. Gassendi’s objection is not simply that the gap between ideas and their objects, once opened, cannot be closed. This is trivial once we grant, as both parties do, that ideas are in some sense the materials for thought. And it is not a problem given, as both parties agree, that there are ways of improving our view of the objects of our ideas. Rather, the issue is which ideas we should take to be the truth conducive ones. This is why Gassendi keeps coming back to the alleged inconsistency of what is apparently perceived clearly and distinctly:

do not say that your Ideas represent things, not just as they are in Idea or in the intellect, but rather as they are in themselves and beyond the intellect. For indeed this is what is in question; and since everyone can say the same thing, you see what discrepancy must be admitted to follow if there is a discrepancy of ideas. You may say that this is limited to things known clearly and distinctly. But the question is, what sort of thing this clear and distinct knowledge is, in which there can be no falsity at all. (III 382a)

Gassendi, of course, has his own answer to propose about what sort of thing can have no falsity at all. It lies in the combination of his version of the Epicurean doctrine that what appears to sense is always true, together with an account of how ideas are acquired from the impressions which the appearances leave in our brains. On this alternate proposal, what method recommends is to begin with the ideas of individual, particular things. For on Gassendi’s account all abstract ideas are fictitious, so that Descartes’s ‘clear and distinct perception’ of his essence is no more a guide to what that essence really is than more obviously constructed ideas:

I add that when someone has in the intellect the Idea of a golden mountain they understand clearly and distinctly that consisting of gold truly pertains to the golden mountain and its immutable nature, essence or form and it cannot be less true and immutable than that a golden mountain consists of gold, that a rational animal is provided with reason. Thus can one move gradually from the nature which is represented in Idea and within the intellect to the nature which is in the thing itself and outside the intellect? Truly only this can be said: What we clearly and distinctly conceive to truly pertain to a golden mountain and its immutable nature, in so far as it is in Idea, we can with truth affirm of the golden mountain to the extent that it is in Idea. And do not say that there is a difference between the golden mountain and the rational animal. For indeed, there is a certain difference, when you go from the ideal state to the real state, or the prison of intellect into the theatre of nature: you can see a rational animal here and there, but a golden mountain nowhere. But as long as you remain in the ideal state, there is no difference of ideas; and you do not have a Criterion by means of which you can judge if a certain idea conforms to a thing existing outside the intellect or not; and you must wait until a Criterion is given in experience in the real state. (III 382a)

This constitutes a denial that Descartes’s proposed internal criteria for the quality of ideas work, together with a claim that there are usable criteria given in experience. The claim that usable criteria are given in experience relies on basic features of Gassendi’s theory of cognition that cannot be addressed here, but the point is clear. Descartes’s response that clear and distinct perception cannot be doubted without leading to skepticism is plausible only if one already accepts the theory of the cognitive faculties argued for in the Meditations. And, since Gassendi takes it that the argument for that theory fails– because it requires trusting the validity of clear and distinct perception to begin with– he has no reason to take Descartes’s anti-skeptical reply seriously. That God’s goodness is incompa tible with the possibility that properly used cognitive faculties are deceptive, is no help in resolving the stand-off that emerges at this point in the debate between Descartes and Gassendi.