Handbook of the History of Logic: - Fordham University Faculty

672 Russell Wahl
an obscure judgement they make concerning the nature of something which they
think exists in the painful spot and which they suppose to resemble the sensation
of pain; but in fact it is the sensation alone which they perceive clearly” [Adam
and Tannery, 1964-76, VIII-1, 22; Cottingham et al., 1985-1991, I, 208]. Descartes
is known for saying that extension and motion are contained clearly in the idea of
material substance, but that heat, color, etc. are not so contained. An idea (or
perception) of material things which included extension and motion, but didn’t
clearly exclude these other things would be clear but not distinct. One which only
included extension and motion would be clear and distinct. After giving a close
approximation to Descartes’ own account of clarity and distinctness, Arnauld and
Nicole added that the obscurity of ideas arises from their confusion, so in the end,
they take clarity and distinctness to be the same thing (70). With respect to
Descartes’ example of an idea of pain being clear but not distinct, they say that
the sensation itself is both clear and distinct. “That the sensation is in the hand”,
which was what was not distinct, is also, they said, not clear (70). The obscurity is
a result of the confusion. So what we are concerned with in clarifying ideas really
involves making them distinct. In retrospect this was also Descartes’ concern.
Given Arnauld’s view of an idea as the mental awareness or perception of a
thing, it is the perceiving that is clear or obscure, not what is perceived. This
point is sometimes overlooked, as Arnauld and Nicole occasionally classify ideas
as clear and distinct simply with respect to their objects. Thus they say that “the
idea each person has of himself as a thing that thinks is very clear, and similarly
the ideas of everything dependent on our thought, such as judging, reasoning,
doubting ...” (70-1) Presumably the suggestion is that when someone is thinking
of these things, these ideas are clear because what is contained in them will strike
the person having them forcefully. Similarly they say that “confused and obscure
ideas are those we have of sensible qualities such as colors, sounds, odors, tastes,
cold, hot, weight ...” (71). Properly speaking whether these ideas are confused
or clear would be relative to the conceiver. Given that they said the idea of pain
confined to the sensation is clear and distinct, it seems possible to have a clear idea
of sensible qualities, provided any bodily location is excluded from them. Similarly,
ideas of external objects can become less obscure by reflection. Descartes himself
speaks of a confused idea of the sun and also a clearer one.
Arnauld and Nicole make a distinction between the comprehension of an idea
and its extension. This distinction, roughly corresponding to the present distinction
between intension and extension, is important for the analyses of propositions
and syllogisms given in Parts II and III. The comprehension of an idea consists
of “the attributes that it contains in itself, and that cannot be removed from it
without destroying it ...” (59). Those features that Descartes would have said
are contained objectively in the idea will be included in this comprehension. For
example, the comprehension of the idea of a triangle will contain extension, shape,
three lines, three angles, and the equality of these three angles to two right angles.
The extension of the idea are “the subjects to which the idea applies” (59). These
include the lower species as well as the individuals. While some have seen this