minuteness, or through the inattention or ignorance of the observer. Agreeably to which, those persons, who study the causes and motives of human actions, may decypher them much more completely, both in themselves, and those with whom they converse, than others can.
Suppose now a person able to decypher all his own actions in this way, so as to shew that they corresponded in kind and degree to the motives arising from the seven classes of pleasures and pains considered in this theory; also able to decypher the principal actions of others in the same way: this would be as good evidence, that motives were the mechanical causes of actions, as natural phænomena are for the mechanical operation of heat, diet, or medicines. Or if he could not proceed so far, but was able only to decypher most of his own actions, and many of the principal ones of others, still the evidence would scarce be diminished thereby, if the deficiency was no more than is reasonably to be expected from our ignorance and inattention, in respect to ourselves and others. Let the reader make the trial, especially upon himself, since such a self-examination cannot but be profitable, and may perhaps be pleasant; and that either according to the seven classes of pleasures and pains here laid down, or any other division, and judge as he thinks fit upon mature deliberation.
It may be of use in such an inquiry into a man’s self, as I here propose, for him to consider in a short time after any material action is past, whether, if he was once more put into the same rigidly exact circumstances, he could possibly do otherwise than as he did. Here the power of imagination will intervene, and be apt to deceive the inquirer, unless he be cautious. For in this review, other motives, besides those which did actually influence him, will start up; and that especially if the action be such as he wishes to have been performed with more vigour or less, or not to have been performed at all. But when these foreign motives are set aside, and the imagination confined to those which did in fact take place, it will appear impossible, as it seems to me, that the person should have done otherwise than the very thing which he did.
Secondly, According to the theory here laid down, all human actions proceed from vibrations in the nerves of the muscles, and these from others, which are either evidently of a mechanical nature, as in the automatic motions; or else have been shewn to be so in the account given of the voluntary motions.
And if the doctrine of vibrations be rejected, and sensation and muscular motion be supposed to be performed by some other kind of motion in the nervous parts; still it seems probable, that the same method of reasoning might be applied to this other kind of motion.
Lastly, To suppose, that the action A, or its contrary a, can equally follow previous circumstances, that are exactly the same,
