An emphatic protest was raised against this theory by the idealistic philosopher George Berkeley (1685-1753). “The idea of man that I frame to myself must be either of a white or a black or a tawny, a straight or a crooked, a tall or a low or a middle-sized man. I cannot by any effort of thought conceive [that is, mentally picture] the abstract idea above described.” It is, truly, a little difficult to _imagine_ an abstract ‘colour’ with all the specific colour-elements left out! Yet the theory is so plausible, as long as process and meaning are confused, that it has been revived again, though in somewhat altered form. The suggestion has been made that an abstract idea is a sort of _composite photograph_, a mental picture which results from the superposition of many particular perceptions or ideas, and which therefore shows the common elements distinct and the individual elements blurred. A passage from Huxley illustrates this view. “An anatomist who occupies himself intently with the examination of several specimens of some new kind of animal, in course of time acquires so vivid a conception of its form and structure, that the idea may take visible shape and become a sort of waking dream. But the figure which thus presents itself is generic, not specific. It is no copy of any one specimen, but, more or less, a mean of the series.” To which we reply that ‘the figure which presents itself’ is as specific and particular as any other idea; only, it _means_ the genus; the anatomist is working under the suggestion of a type, of a composite picture that will make a diagram in a text-book or monograph; and his idea is abstract in virtue of this determination and context, and not because it pictures the mean of a series.