Gewirth, Alan (1943). Clearness and Distinctness in Descartes. Philosophy 18 (69):17 - 36.
Whereas Leibniz demands that the criterion be "palpable," "mechanical," and lacking in "even the least difficulty," and declares that "there is no need for prolix discussions concerning our prejudices," Descartes states already in the Discourse that "there is some difficulty in noting well what are the things which we conceive distinctly," and tells Gassendi that "I do not believe that those who are so little concerned with the uprooting of prejudices that they complain that I have not spoken of them 'simply and in few words,' will readily perceive the method whereby we can distinguish that which is really perceived clearly from that which is only thought to be clearly perceived.
The setting forth of criteria of clearness and distinctness, then, will for Descartes neces sarily involve a psychological discipline. Among his basic comments concerning formal logic and the "synthetic" method of demonstra tion, both of which he opposed to his own method, were that the former permits the mind to "go on a holiday from the evident and attentive consideration of the inference itself," and the latter "wrests assent from the reader, no matter how unwilling and per tinacious he may be."6 Both of these methods, in their formal character, thus realize Leibniz's ideal, but only, Descartes holds, at the expense of losing all heuristic value.
For example, not every idea which is interpreted to be representative of God is clear and distinct. The idea will have these qualities only if "we do not put anything fictitious into it, but note those things alone which are really contained in it, and which we evidently perceive to pertain to the nature of the most perfect being." Among these "real" attributes Descartes lists "eternal, omniscient, omnipotent, source of all goodness and tru creator of all things, and in sum having in himself all those things in which we can clearly note some perfection which is infinite, or terminated by no imperfection."' On the other hand, the idolaters' "idea of God," which in its direct content representatively includes, together with perfection, such attributes as vindictiveness and corporeality, is obscure and confused.
5. Once an idea has what we have seen to be the minimum of clearness and distinctness, it can become clearer if, while it is still interpreted to be representative of the same object, its direct content comes to include additional attributes necessarily connected with the interpretive content. "The more attributes we apprehend in the same thing or substance, the more clearly do we know it."' And by the same token, the idea will become more distinct, for the richer its content, the more is it distinguished from what is other than it: "A concept is not made more distinct by the fact that we compre hend fewer things in it, but only by the fact that those things which we do comprehend in it we accurately distinguish from all others
This variation in degree reveals another distinction, in addition to that between direct and interpretive contents, required to give clearness and distinctness a normative basis. This other distinction is between the explicit and implicit contents of an idea. We have seen that although a clear and distinct perception is "integral and complete," it nevertheless can become more clear, i.e. even more "complete." The limit of such increase is an "adequate" idea, in which are representatively "contained absolutely all the properties which are in the thing known."4
Only God can have such adequate knowledge; the human mind is incapable of it, although it may have "complete" knowledge.
Thus man may have a complete and hence a clear and distinct idea of God although this idea is by no means adequate to God's infinite perfection, just as "we do not doubt that one unlearned in geometry has the idea of a whole triangle, when he understands it to be a figure comprehended by three lines, although many other things can by geometers be known about that triangle, and be noted in the idea of it, of which he is ignorant."5
For a direct content not to "contain absolutely all the properties which are in the thing known" is possible only because of the logical orientation of Descartes's view of ideas. Metaphysically, of course, an idea refers beyond itself to a thing which the mind can never perceive directly; but in denying adequacy to human cognition Descartes is not rely ing exclusively, or even primarily, upon this basic fact; rather, he is referring to what can be ascertained in ideas themselves. Now for a strictly psychological position, an idea is precisely and exhaustively that content of which the mind is at any time aware, so that (putting Descartes's definition of adequate knowledge in terms of ideas and perceptive acts) to speak of a perception which is not aware of every thing contained in an idea is a contradiction in terms.
For Descartes, on the other hand, a distinction is possible between those ideas which are "fictitious," i.e. arbitrarily compounded by the mind itself, and those which the mind merely discovers without adding to their "objective reality." It still remains true that every idea not only depends upon the mind for its existence, but consists in that very content of which the mind is directly aware.
But once thus constituted as a direct object of perception, an idea of the latter sort is, with regard to its further significance, an independent logical entity containing within itself a system of implications, of simple natures and their relations, which deduction may gradually reveal, and which indeed it is the task of science progressively to discover.
The ultimate conceptual elements of ideas are called by Descartes "simple natures." They include, on the side of material things, such concepts as "figure," "extension," "motion," and on the side of mental phenomena, "cognition," "doubt," "ignorance," "volition."
Unlike composite ideas, in which it is possible to discriminate from one another not only direct and interpretive contents, but also various parts of the direct content, the necessity of whose con nection with one another in the idea is not self-evident, the simple natures cannot be misinterpreted, for it is impossible to discriminate in them a direct and an interpretive content.
To think of these simples at all is to think of them completely, and hence clearly; similarly, their very simplicity makes it difficult for the mind to confuse them with, i.e. interpret them as, anything "other" than themselves, so that they are perceived distinctly as well.4 Since all composite ideas involve these simples, it follows that to attain a clear and distinct perception of any composite idea requires the reduction of the idea to these self-evident elements and then the perception of the precise way in which they are combined in a necessary nexus to form the idea originally in question.
An excellent example of this process is the famous opera tion upon the wax in the Second Meditation. It is required to ascer tain the essential nature of matter. A direct content which is inter preted to be representative of matter is chosen, consisting in the various sense qualities which the wax initially presented. Then these qualities are put through a series of reductions to see whether they and the interpretive content "so depend upon one another, that one can in no way be changed while the other remains unchanged."' It is found that the sense qualities are changed, although the wax still "remains the same." Hence, those qualities are essentially "other" than the wax, and the interpretive perception of them as representing the essence of the wax was not distinct. This "identity" of the wax throughout the changing of the direct content, which is greatly emphasized by Descartes, can be understood only through the interpretive aspect of his doctrine of ideas. It is because the interpretive perception is held constant that the reductive process can be viewed, in the methodological context, as going from acci dental to essential attributes of the same object, and not from one set of ideas to another set wholly unrelated thereto. The process consists, then, in gradually divesting the direct content interpreted as representing a certain object of the "forms external" to that object, i.e. of those qualities with whose denial the object can still be conceived, so that there is no necessary connection between the object and those qualities. The end of the process comes when a direct content is attained which survives every reductive device, remaining so long as the object can be conceived, and without which the object can no longer be conceived. This direct content is hence necessarily connected with the interpretive content whereby the mind thinks of the object in question, and constitutes th essential definition of that object.
And only in virtue of such a reductive process is the resultant perceptive act clear (as attaining the essence of the object, in that the direct content which is actually representative of the essence of the object which it is interpreted as representing has been made "present and open to the attending mind") and distinct (as excluding everything "other than" what is essential).
The wax is thus ascertained to consist essentially of exten sion and mobility, not of any peculiar colours, sounds, and tastes; hence, at the conclusion of the reductive process whereby the sense qualities are removed, Descartes writes that the perception of the wax "can be either imperfect and confused, as it was before, or clear and distinct, as it now is, in so far as I attend less or more to the things of which it consists."