tion; and since in this we presuppose with perfect certainty identity with us, we do not hesitate to attribute to it unchanged all the affections of will which we know in ourselves, and speak at once of its desire, aversion, fear, anger, hatred, love, joy, sorrow, longing, &c. On the other hand, whenever phenomena of mere knowledge come to be spoken of we fall at once into uncertainty. We do not venture to say that the animal conceives, thinks, judges, knows: we only attribute to it with certainty ideas in general; because without them its will could not have those emotions referred to above. But with regard to the definite manner of knowing of the brutes and the precise limits of it in a given species, we have only indefinite conceptions, and make conjectures. Hence our understanding with them is also often difficult, and is only brought about by skill, in consequence of experience and practice. Here then lie distinctions of consciousness. On the other hand, a longing, desiring, wishing, or a detesting, shunning, and not wishing, is proper to every consciousness: man has it in common with the polyp. This is accordingly the essential element in and the basis of every consciousness. The difference of the manifestations of this in the different species of animal beings depends upon the various extension of their sphere of knowledge, in which the motives of those manifestations lie. We understand directly from our own nature all actions and behaviour of the brutes which express movements of the will; therefore, so far, we sympathise with them in various ways. On the other hand, the gulf between us and them results simply and solely from the difference of intellect. The gulf which lies between a very sagacious brute and a man of very limited capacity is perhaps not much greater than that which exists between a blockhead and a man of genius; therefore here also the resemblance between them in another aspect, which springs from the likeness of their inclinations and emotions, and assimilates them again to each other, sometimes appears with surprising promi-
