Reid's leading design was to overthrow scepticism and idealism. In furtherance of this intention, he proposed to himself the accomplishment of two subsidiary ends,--the refutation of what is called the ideal or representative theory of perception, and the substitution of a doctrine of intuitive perception in its room. He takes, and he usually gets, credit for having accomplished both of these objects. But if it be true that the representative theory is but the inevitable development of the doctrine which treats the perception of matter analytically, and if it be true that Reid adopts this latter doctrine, it is obvious that his claims cannot be admitted without a very considerable deduction. That both of these things are true may be established, we think, beyond the possibility of a doubt. In the first place, then, we have to show that the theory of a representative perception (which Reid is supposed to have overthrown) is identical with the doctrine which treats the perception of matter analytically;--and, in the second, we have to show that Reid himself followed the analytic or psychological procedure in his treatment of this fact, and founded upon the analysis his own doctrine of perception. _First_, The representative theory is that doctrine of perception which teaches that, in our intercourse with the external universe, we are not immediately cognisant of real objects themselves, but only of certain mental transcripts or images of them, which, in the language of the different philosophical schools, were termed ideas, representations, phantasms, or species. According to this doctrine we are cognisant of real things, not in and through themselves, but in and through these species or representations. The representations are the immediate or proximate, the real things are the mediate or remote, objects of the mind. The existence of the former is a matter of knowledge, the existence of the latter is merely a matter of belief. To understand this theory, we must construe its nomenclature into, the language of the present day. What, then, is the modern synonym for the "ideas," "representations," "phantasms," and "species," which the theory in question declares to be vicarious of real objects? There cannot be a doubt that the word _perception_ is that synonym. So that the representative theory, when fairly interpreted, amounts simply to this;--that the mind is immediately cognisant, not of real objects themselves, but _only of its own perceptions of real objects_. To accuse the representationist of maintaining a doctrine more repugnant to common sense than this, or in any way different from it, would be both erroneous and unjust. The golden rule of philosophical criticism is, to give every system the benefit of the most favourable interpretation which it admits of.