desire for a horse was an example. Authors of our second and third classes are those who hit upon this kind of a desire. Yet a large number of mental states other than states of pleasure do tend innately to acts that should reproduce their objects. The impulses of children to mimic and to imitate are marked examples of such. Since it is the fundamental function of every mental event to tend to some act, since such a tendency is its own reason-to-be, biologically, we may surmise that a much larger proportion of our ideas than commonly we take note of do, during the moment of their occurrence, fall fundamentally under the category of desire; rightfully so fall, though their distinguishing tendency, being swamped in the subsequent trend of our thoughts, may consequently be lost sight of. Ideas of pain usually tend to acts that should discontinue pains like those thought of; hence, usually, ideas of pain are not desires. Yet ideas of pain may be so joined with other ideas that the whole concept shall be a genuine desire.
Our worm, then, could desire ; for on his brain could be made impressions, which, when revived in memory, would tend to acts that should bring about experiences like those from which such impressions sprung. He could also hate; for from the foregoing it will plainly follow that aversions, or hates, are mental states that tend toward acts that should discontinue their objects.
It may still be contended that our worm would not itself know any difference between such desires and such aversions, transacted in terms of a single sense ; that, as psychic experiences to be judged of themselves, they would not be different. But we further point out that even under this aspect the desires and aversions of the worm would display characteristics of makeup markedly contrasting with each other. Even the muscular activities executed in pursuance of these desires and aversions would betray corresponding characteristics. Our lips act differently when pressing a luscious cherry than when, accidentally, we have bitten a bitter one. We do not shake hands as we strike. The whole muscular deportment of a child actively at play is far different from one flying in fright from a dog. If all our conscious states should drop out except those of our muscle
