Page:Philosophical Review Volume 25.djvu/841

No. 6.] standard which would be attained by putting all human knowledge into one detailed system, were that possible. Moreover, the bulk of ideas handed down through scientific and general literature are based on a far wider experience than is available for the individual.

Notions or passing ideas are ideal—or perfunctory—in various degrees, and, when we speak of a personal idea, we generally mean the person's habitual idea, giving him credit for what it appears as in his sincere and intelligent moments of reflection, and for its various connections with other ideas of which he is aware, though he may not think of them all simultaneously. Similarly, when we speak of a cultural idea, we should understand that idea as it is common to the best minds of an age, and thus tends to possess a standard value in intellectual history, if not in abstract science. A cultural idea may be said to become scientific, when its application to a given particular thing, person, system, or group, or to some concrete type or abstract mode of being, is understood and agreed to by all persons who have made a serious study of the subject in question. Thus, to my mind at least, the fundamental differentiation of scientific from unscientific thinking does not rest on the discovery of laws, but on the accurate description of object-matters whose causal connections may not yet have been discovered.

The only way in which ideas can be conveyed from mind to mind (or, more literally speaking, evoked in one mind through physical means employed by another) is by the use of recognized signs. These are representations, in so far as they have some intended likeness to their object-matter; symbols, in so far as they suggest the object-matter through habitual association with something which does not resemble it. Pictures are, of course, representations (of things, in their visible aspects), while terms, verbally considered, are pure symbols. Logical ideas, or the understandings of terms, combine certain abstractly representative features with the direct symbolic references of the