Zhang (2019) Descartes and Husserl on “Clear and Distinct”

Zhang, Haojun (2019). Descartes and Husserl on “Clear and Distinct”. Husserl Studies 35 (1):51-72.

 

The expression “clear and distinct” is used by Descartes and Husserl when they talk, respectively, about the truth of an idea and the evidence of judgment. Although for both authors the words “clear” and “distinct” are juxtaposed with the conjunction “and,” their status is not actually equal.

For Descartes, the status of “distinct” is epistemically higher than that of “clear.” For Husserl, on the contrary, the status of “clear” is higher than that of “distinct.” 

I will show that Husserl’s Neo-Cartesianism, assuming that we accept such a label, corresponds to a kind of revolution in respect to some of the principles of Descartes’ philosophy.

The reversal of the relationship between clarity and distinctness squares with the role Husserl ascribes to sensibility as our fundamental access to the world, and thus as the ground for evaluating the truthfulness of our judgments—a role which is evidently at odds with Descartes’ general philosophical system.

While in Descartes the guarantee that our “ideas” (ideae) have a real reference is provided by their clarity and distinctness, and such clarity and distinctness are never achieved in perceptual acts or, more precisely, in sensuous perceptual acts, in Husserl the reference of our “representations” (Vorstellungen) is precisely warranted by the fact that they find support in the contents of sensuous acts.

It suffices to point out that, similarly to Descartes’ ideas, Husserl’s representations are ways to refer to reality. However, while in Descartes it seems that ideas never “directly” put us into touch with reality, in Husserl there are intuitive modes of representa tion, and signally sensuous perceptions, that are considered to be able to give the things themselves. This is an aspect of difference between Husserl’s and Descartes’ general epistemology which has to be kept in mind in order to understand the difference in their ordering of clarity and distinctness.

In addition, we should also note that an authoritative interpreter, Ste ven Nadler, has proposed to read Descartes’ theory of ideas as a form of Direct Realism (Nadler 1989, 2006). [ Nadler, S. (1989). Arnauld and the Cartesian philosophy of ideas. Princeton: Princeton University Press]

1 Descartes on “Clear and Distinct”

There is no doubt that in modern philosophy it [to juxtapose clara with distincta] mainly derives its importance, and at least partially its meaning, from Descartes.

It is especially because of the way Descartes uses the so called “Rule of Truth” (henceforth RoT) based on clear and distinct ideas in the Dis cours de la Méthode (1637), and even more so in the Meditationes de prima philos ophia (1641), that the expression “clear and distinct” became famous—as well as infamous.

However, one cannot avoid noticing that in those works Descartes is far from giving a satisfactory definition of what “clear” and “distinct” mean and how they conjoin. Although, as Kurt Smith has carefully shown, the concept of “clear and distinct” was already being developed at the time the Regulae ad directionem ingenii was being composed (plausibly around 1628), among the works published during Descartes’ lifetime the Principia philosophiæ is the one which most clearly and explicitly dealt with the concept.

In §45 of the first chapter, “The Principles of Human Knowledge,” of this later work, Descartes says:

Indeed there are very many people who in their entire lives never perceive anything with sufficient accuracy to enable them to make a judgment about it with certainty. A perception which can serve as the basis for a certain and indubitable judgment needs to be not merely clear but also distinct. I call a perception “clear” when it is present and accessible to the attentive mind—just as we say that we see something clearly when it is present to the eye’s gaze and stimulates it with a sufficient degree of strength and accessibility. I call a perception “distinct” if, as well as being clear, it is so sharply separated from all other perceptions that it contains within itself only what is clear. (AT VIIIA, p. 22/ CSM I, pp. 207–8)

Clear and distinct: properties of a perception that can serve as the basis for a certain and indubitable judgment

certainty might be a property of judgment

clear: it is present and accessible to the attentive mind

we see something clearly when it is present to the eye's gaze [the attentive mind] and stimulates it [the mind] with a sufficient degree of strength and accessiblity.

distinct: clear + a perception is so sharply separated from all other perceptions that it contains within itself only what is clear  

This is to say that if we could perceive an object with sufficient accuracy concerning its details in an immediate intuition, then the perception would be clear, i.e. the object would be present clearly in our perception. However, if we do not only perceive the object clearly, but also separate it sharply from other things, then the perception would be not merely clear, it would also be distinct.

An idea is distinct if it is either a simple idea, or a complex idea wherein all the components are clear and distinct as well, including the relations between its components.

In this regard, we should remember that, in the Regulae, simple ideas correspond to “simple natures”, i.e., broadly speaking, things or properties which cannot be analyzed any further, cannot be broken up into other ideas. In the Meditations and in the Principles, Descartes seems no longer to refer directly to simple natures. Rather, in these later works we find a view according to which the only clear and distinct ideas are those referring to intellectual beings, while all corporeal and all sensible ideas—ideas coming, even in part, from the senses—can never be clear and distinct (CSM II, p. 305).

At §46 of the Meditations, Descartes writes that “a perception can be clear with out being distinct, but not distinct without being clear” (AT VIIIA, p. 22/CSM I, p. 208).

Therefore, it seems that the status of distinctness is higher than that of clarity in reference to the degree of explicitness of perception. Descartes demonstrates this by using pain as an example. He says that when some one feels pain, the perception he or she has of it is probably very clear, but is not definitely distinct. This is because one could confuse her perception with an obscure judgment that she has made about the nature of something which she thinks exists in the area which is in pain, which she supposes to cause the sensation of pain and can only be perceived by her clearly, although its connection with a certain part of the body is not clear (ibid.)

In the case we are currently considering, i.e. pain in a part of the body, the idea is complex and confused, because it puts together a mental idea, namely pain, and a physical one, namely a part of the body. Even assuming that, taken separately, both could be perceived in a clear and distinct way, there is no clear nor distinct intuition of their connection. To this we should add that the idea of a body is in general clear only if we reduce the latter to its mathematical features, i.e. if we reduce it to what concerns their shape, size, and number. Other “bodily ideas” are somehow inevitably confused, if not unclear.

Now, if we may return to the example of bodily pain, for Descartes we are merely used to a certain connection between a certain feeling of pain and its localization, i.e. the knowledge concerning the localization of a pain is due to habit, not to under standing. This means that the idea of, for example, “pain at the left ankle” is par tially clear—we are (quite) sure that there is pain!—but fundamentally confused. Indeed, as has been aptly pointed out by Kurt Smith (2001), it is ambiguous as to whether or not Descartes is speaking about the idea of pain simply as sensation (we could say as “qualia”), or of pain as localized. If the two “ideas” could be separated, i.e. conceived as distinct from one another, one could perhaps say that, if we isolate pain and refrain from localizing it, we can achieve a clear and also distinct idea of pain alone. However, this does not seem to be the case for Descartes. At least, he does not seem to consider this possibility. This is probably because pain cannot be conceived, felt, or even be imagined, without any reference to corporeality.

Now that we have gained a general view of what “clear and distinct” means in Descartes’ philosophy, let us consider Descartes’ epistemological theory of ideas in its most famous, as well as notorious, application in one of the most well-known, and likewise notorious, arguments of the whole history of Western philosophy.

At the very beginning of the Meditations on First Philosophy, Descartes claims that the purpose of his book is to prove the existence of God and the real distinction between mind and body.

The realization of this goal depends, to a great extent, on a general epistemological rule: “whatever I perceive very clearly and distinctly is true” (AT VII, p. 35/CSM II, p. 24).

It is through this rule that Descartes demonstrates first the existence of God, and then the real distinction between mind and body. This rule serves as the cornerstone of Descartes’ “demonstrative” logic and theoretical system.

It is well-known that Descartes “demonstrations,” at least in the field of metaphysics, are quite problematic. As a matter of fact, this was pointed out very soon by his objectors, causing Descartes to repeatedly insist that his demonstrations should not be understood as if they were aimed at taking us from given truths to unknown truths. In Descartes’ metaphysical reflections we do not reason in a demonstrative way, but rather in a heuristic way, i.e. Descartes’ reflections should lead us to see more clearly and distinctly, and sometimes even to almost discover what is already in our mind.

Namely, we are interested in the rule according to which clear and distinct ideas are always true, so that we can be certain that what they “show” exists in the way it is shown. However, our pur pose here is neither to criticize nor to defend Descartes’ RoT, and we will limit our selves to pointing out the reasons for the hierarchy between clarity and distinctness Descartes joins with it.

We know that, for Descartes, the only clear and distinct ideas are those which are derived from purely “intellectual intuitions.” Descartes famously opposed the dominant Aristotelian and Thomist tradition, according to which whatever we have in mind was first in the senses, i.e. all ideas come from some kind of sensuous experience.

On the contrary, Descartes believes that only ideas which are not mixed with ideas coming from the senses offer us something which can certainly be true. In other words, only “the pure use of the intellect, independent of the senses” (Hatfield 2002, p. 73) can allow us to gain certainty and knowledge.

This being the case, it is easy to understand why we can establish that clear ideas which are not also distinct do not provide knowledge. If we leave aside all ideas which directly refer to something physical, or bodily, we are left with ideas of merely mental “things” (thoughts, memories, desires, etc.—what Husserl’s philosophy would call noeses) and with mathematical and logical ideas. As for the ideas of mental things, however, we should observe the following.

At first sight it could seem reasonable to assert that clarity and distinctness of mental states and events go hand in hand with their presence, and thus their existence. This also seems to be confirmed by the Cartesian slogan that we can doubt that which we think, but not our thinking of it. Given that thinking can be found in different modes, whenever one of these modes is present, we should have a clear and distinct idea of it.

This is, however, not really the case. Clearly it is possible to confront complex mental phenomena, so that we cannot properly distinguish all their components. There are, however, two sides to this complexity.

The first aspect is relatively harmless for what we are considering here, namely, whether we can have clear and distinct ideas of our noesis as noesis, i.e. whether we are able to distinguish one mental state or event from any other, so that we can clearly see what kind of state it is. For example, we can have an ambiguous attitude towards a certain thing and be unable to state whether we desire or fear it. Such confusion is however due to a confusion concerning what the object is. Roughly, we can say that we have confused feelings and attitudes towards something either because we do not really understand what the object is, or because we can consider it from different perspectives (for example, I desire the cake for the pleasure it gives me, but I also fear it because it will interfere with my desire to lose weight).

In any case, to affirm with certainty the existence of a certain mental state requires that we do not simply have a clear intuition of our complex mental state, but also that we can precisely discern all mental states (in case there are many) involved in such complexity.

With that said, since so many of our mental states derive from our conjunction with a body, as the Passions of the Soul shows, it is far from easy to distinguish all components of our mental lives occurring at a given time. It follows that mental states can only rarely be intuited in a clear and distinct way.

Indeed, the only clear and distinct idea of ourselves Descartes considers is that of ourselves as pure intellect (Meditation VI)—and it is the capacity to see ourselves clearly and dis tinctly as pure intellect, and not as, for instance, desiring, imagining, perceiving, or sitting by the fire while wearing a winter dressing-gown, which in Descartes’ sys tem allows both the apodictic affirmation of our existence and the possibility of our immortality.

Beside the idea of pure intellect (which applies, though in different degrees of perfection, to God as well as to us, and also to the angels), the only other ideas we can have a clear and distinct perception of are those of logical and mathematical objects broadly conceived (geometrical figures, numbers, logical laws, and, in general whatever can be part of a formula or of an algorithm), i.e. the objects of the so-called mathesis universalis.

In the field of mathematics, we could say that we always have clear ideas. In other words, we either get the meaning of an expression or not. If we don’t, we cannot say that the idea is given in an obscure way. Rather, it is not given at all. We have, thus, no idea.

However, it can also happen from time to time that a (clearly) given idea is not distinct. For example, I can have the idea of a triangle. As long as I do not spell out what all the parts of a triangle are, and how they precisely relate to one another, my idea of a triangle is not distinct. In this case, though, we should not consider the idea to be confused, as it would be when we have corporeal ideas or mixtures of corporeal and intellectual ideas. Rather, the mere idea of a “triangle” is vague, because we do not know what kind of triangle we mean, nor what its precise measurements and inner proportions are.

We can also say that we have a “general” idea of a triangle, and, since every triangle must be in one specific way or another (as was famously pointed out by Berkeley in opposition to Locke), such a general idea, by itself, is not sufficient to affirm its truth. Moreover, since I do not analyze its inner constitution, I could unwittingly think of it as having certain features it does not have. For example I could unwittingly believe that a triangle has the feature of having the total sum of its angles as 150 degrees. Therefore, one could here endorse Kurt Smith’s General Theory, and maintain that, at least in the field of purely intellectual ideas, distinctness amounts to a kind of maximum degree of clarity (see Smith 2001, pp. 294–295): I only really have a clear idea of something when I clearly, i.e. explicitly, intend all its parts and their reciprocal relationships.

Mistakes are never made by perception but rather by the will, which judges a given idea as true (or false). Descartes emphasizes the function of will when he “proves” the RoT. For his part, correct judgment depends on two kinds of faculties, namely, intellect (the faculty of knowledge or understanding) and free will (the faculty of free choice).

Like Augustine, Descartes believes that God is not the source of our mistakes. Intellect and will are not “fallen” or corrupted, since they are given by God. The source of our errors (and sins) rather consists in a failure to utilize our free will appropriately. (AT VII, pp. 56–62/CSM II, pp. 39–43).

The function of the intellect is to cognize, to know, to apprehend the object—to acquire the idea of it—while the function of the will is to affirm or deny ideas and the relations among them, or to refrain from making a judgment. More precisely, the role of will is to assent to [~에 대해 동의하다] an idea or not, and this means that, provided that an idea is given, we affirm that there is something corresponding to it.

For Descartes, if the will performs a judgment on the basis of what we perceive clearly and distinctly, we can achieve truth and avoid error. But if the will goes beyond the domain of clear and distinct perception and makes a judgment on what we do not understand or cognize clearly and distinctly, either by affirming or denying it, then we can fall into fallacy. Actually, we can make a correct judgment even if the idea is not clear and distinct, but in this case we are not adequately justified in making that judgment. Therefore, we can assert the truth without properly knowing it.

On the basis of what we have seen so far, we should then be able to better understand why Descartes considers distinctness to be based on clarity and also to be higher than clarity (or at least a higher degree of clarity).

We can have clear ideas which are confused, and thus we can make mistakes if we judge true what appears in them. This is especially apparent when we have ideas which are at least partially derived from the senses. However, confusion is possible also in the realm of purely intellectual ideas, such as when we have a clear, but general, idea of a triangle, but we do not analyze it carefully, so that we inadvertently mix it with the idea of a specific kind of triangle, such as a right triangle, of which we know that the square of the hypotenuse equals the sum of the squares of the two other sides. Because of this confusion, we can mistakenly judge that this property, proved by the Pythagorean theorem, applies to any triangle.

On the contrary, if we observe more carefully the idea we have in mind, we see that we are mixing two partially essentially overlapping ideas, and thus whatever we affirm of one of them is not necessarily valid for the other. Hence, we should at least refrain from judging until further distinct evidence is reached.

Briefly, we can say that, following Descartes, we should only make judgments about objects which we can be sure to have analyzed in all their parts, properties, and internal relationships. This kind of analysis is performed by the intellect on the idea we have of the object we have in view—be this abstract or concrete, ideal or real. In this way, we can find another important feature of Descartes’ general theory of ideas which is of fundamental importance for understanding his hierarchy between distinctness and clarity and his difference from Husserl.

So far we have not considered one of the main features of Descartes’ theory of ideas, namely the distinction between the formal and the objective reality of ideas. As is well-known, Descartes rejects a “pictorial” understanding of ideas, as if they were copies of things. However, ideas have an “objective reality” in our mind which can correspond a “formal reality” in the world. More precisely, all ideas have a for mal reality, but this can be different from what we judge it to be. The pivotal example is that of external, material objects: it could be that what we “see” as external, as existing “over there”, is in truth a phantasm created by our mind, or by that of an evil god. This being the general framework of Descartes’ ontology, his theory of mind has normally been considered as representationalist and his epistemology as internalist. The prevailing interpretations in this regard are not undisputed. However, for our current aims it is just important to stress that, whether representationalist and internalist or not, Descartes’ understanding of ideas does not consider “blind” ideas and their “intuitive” fulfillment. That is, in Descartes’ general framework we must judge whether the ideas we entertain in one way or another are true or not, and it is not an issue whether an intuition of the “things themselves” can confirm our ideas.

This last remark already allows us to intuit that there is, at least apparently, a quite profound difference between Descartes’ theory of ideas and Husserl’s phe nomenological epistemology—and that such a difference is possibly at the basis of the divergence between their two hierarchies as regards clarity and distinctness. In order to better understand it, and to appreciate the more systematic significance each hierarchy entails, we must now consider Husserl’s treatment of clear and distinct evidence.