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 answers to them are craved by the developed faculties of knowledge. The account of the manner in which these inquiries were fairly raised in modern times, is a remarkable chapter in the history of the mind of man and of philosophy, which we now proceed to sketch.

The modern metaphysical controversy with scepticism has turned upon the prevalent doctrine with regard to what is the immediate object of knowledge—a very curious part of the general theory of the intellect. An acquaintance even with the works of Dr. Reid is sufficient to render the reader familiar with the fact of the very general reception, previous to the time of that philosopher, of the doctrine of representative images or ideas, to account for all knowledge, except that which we have of our own mental operations, of which last it was usually granted that we are directly conscious. Mind, it was supposed, can be conscious only of itself, and the hypothesis of a representative knowledge was invented to explain the phenomenon—which theorists regard as the grand difficulty of intellectual psychology—of a conscious intelligence, a large part of whose knowledge is not exclusively self-contained.

The hypothesis of mental representations, distinct at once from the percipient mind and from the object per-