“An idea may be considered as existing either in the mind or out of it” (p. 18). It is very improper to give the name of idea to anything out of the mind, as words, gestures, and other outward natural or conventional signs.
“Ideas are, first, either true or false. They are true when they conform with their objects, false when they do not. But since this conformity is always with the objects as represented in our minds, and not as they may be in reality, we may, with this explanation, admit the opinion of those who pretend that there are no false ideas” (p. 20). This explanation has no grounds. Ideas are never compared with the objects as represented in our minds. Such a comparison would have no meaning; for the object as represented in our minds is nothing else than a subjective form identical with the idea itself. When philosophers say that there are no false ideas, they mean that ideas always conform to their object as it shows itself. This is the common and true doctrine. Even the author himself, probably forgetful of what he had said in this passage, teaches, a few pages later, that “we cannot err in perceiving or in feeling” (p. 23).
“An idea is distinct when it can be readily separated from any other idea, ... and is confused when the object cannot be distinctly determined” (p. 21). We believe that ideas are called “distinct,” not when they can be readily separated from one another (a thing which we cannot even conceive), but when they represent distinctly their object in all its particulars. In the contrary case, they are called “confused.”
“The extension of an idea signifies the whole collection of the individuals which the same idea embraces” (p. 21). This is false. The extension of an idea is the range of its universality; and we have already remarked that universality is not a collection of individuals. Moreover, it is comprehension that “embraces” whatever it comprehends, while extension embraces nothing, but only “reaches” potentially the terms to which it extends, inasmuch as the idea is applicable to them.
“When, in order to form a species, we collect several individuals having common properties, we perform an operation which is called generalization” (p. 22). This is very wrong. Generalization, says Webster, “is the act of reducing particulars to their genera”; and this cannot be done by collecting individuals, but only by leaving aside whatever is individual, [pg 238] and retaining that which is common.
“When the mind, after having compared two ideas, declares their consistency or their inconsistency, it makes a judgment” (p. 23). The mind properly compares, not the ideas themselves, but their objects as cognized. Two ideas may be found consistent, and yet no judgment be made. Thus, I see that the idea of whiteness is consistent with the idea of paper; but does it follow that my mind judges the paper to be white? Not at all. It might as well judge the paper to be green; for the idea of green is no less consistent with the idea of paper. It is therefore evident that the mind in judging does not declare the consistency or inconsistency of two ideas, but affirms the mutual inclusion or exclusion of two objective terms as apprehended.
“Nothing is more obscure or less useful than such classifications (of categories)” (p. 24). The author should have been loath to condemn what all great philosophers have praised. He might have considered that classification, as in all the other sciences, so also in philosophy, brings clearness, and that clearness is very useful.
“Reasoning is said to be immediate when no comparison is needed” (p. 30). How can there be reasoning without the comparison of two terms with a third?
“Method is that operation of the mind, etc.” (p. 44). Method is the order followed in the operation; the operation itself is the use of method.
“Induction ... is an operation of the mind inducing us to affirm, etc.” (p. 46). Why “inducing us”? It is the conclusion that is induced, not ourselves.