I assure my readers, that I have no desire to treat with disrespect and contumely the opinions of great or good men; but the distinction in question, and the assertion and exhibition of the higher prerogatives of reason, as an essential constituent of our being, are so vitally important, in my apprehension, to the formation and support of any rational system of philosophy, and--no less than the distinction before treated of--so pregnant of consequences to the interests of truth, in morals, and religion, and indeed of all truth, that mere opinion and the authority of names may well be disregarded. The discussion, moreover, relates to facts, and to such facts, too, as are not to be learned from the instruction, or received on the authority, of any man. They must be ascertained by every man for himself, by reflection upon the processes and laws of his own inward being, or they are not learned at all to any valuable purpose. We do indeed find in ourselves then, as no one will deny, certain powers of intelligence, which we have abundant reason to believe the brutes possess in common with us in a greater or less degree. The functions of the understanding, as treated of in the popular systems of metaphysics, its faculties of attention, of abstraction, of generalization, the power of forethought and contrivance, of adapting means to ends, and the law of association, may be, so far as we can judge, severally represented more or less adequately in the instinctive intelligence of the higher orders of brutes. But, not to anticipate too far a topic treated of in the Work, do these, or any and all the faculties which we discover in irrational animals, satisfactorily account to a reflecting mind for all the _phenomena_ which are presented to our observation in our own consciousness? Would any supposable addition to the _degree_ merely of those powers which we ascribe to brutes, render them _rational_ beings, and remove the sacred distinction, which law and reason have sanctioned, between things and persons? Will any such addition account for our having--what the brute is not supposed to have--the pure _ideas_ of the geometrician, the power of ideal construction, the intuition of geometrical or other necessary and universal truths? Would it give rise, in irrational animals, to a _law of moral rectitude_ and _to conscience_--to the feelings of moral _responsibility_ and _remorse_? Would it awaken them to a reflective self-consciousness, and lead them to form and contemplate the _ideas_ of the _soul_, of _free-will_, of _immortality_, and of God. It seems to me, that we have only to reflect for a serious hour upon what we mean by these, and then to compare them with our notion of what belongs to a brute, its inherent powers and their correlative objects, to feel that they are utterly incompatible--that in the possession of these we enjoy a prerogative which we cannot disclaim without a violation of reason, and a voluntary abasement of ourselves--and that we must therefore be possessed of some _peculiar_ powers--of some source of ideas _distinct_ from the understanding, differing _in kind_ from any and all of those which belong to us in common with inferior and irrational animals.