Aristotle too[12], when he made virtue to consist in practical habits, had it probably in his view to oppose the doctrine of Plato, who seems to have been of opinion that just sentiments and reasonable judgments concerning what was fit to be done or to be avoided, were alone sufficient to constitute the most perfect virtue. Virtue, according to Plato, might be considered as a species of science, and no man, he thought, could see clearly and demonstratively what was right and what was wrong, and not act accordingly. Passion might make us act contrary to doubtful and uncertain opinions, not to plain and evident judgments. Aristotle, on the contrary, was of opinion, that no conviction of the understanding was capable of getting the better of inveterate habits, and that good morals arose not from knowledge but from action. Footnote 12: See Aristotle Mag. Mor. lib. i. ch. 1. III. According to Zeno[13], the founder of the stoical doctrine, every animal was by nature recommended to its own care, and was endowed with the principle of self-love, that it might endeavour to preserve, not only its existence, but all the different parts of its nature, in the best and most perfect state of which they were capable. Footnote 13: See Cicero de finibus, lib. iii. also Diogenes Laertius in Zenone, lib. vii. segment 84. The self-love of man embraced, if I may say so, his body and all its different members, his mind and all its different faculties and powers, and desired the preservation and maintenance of them all in their best and most perfect condition. Whatever tended to support this state of existence was, therefore, by nature pointed out to him as fit to be chosen; and whatever tended to destroy it, as fit to be rejected. Thus health, strength, agility, and ease of body, as well as the external conveniencies which could promote these, wealth, power, honours, the respect and esteem of those we live with, were naturally pointed out to us as things eligible, and of which the possession was preferable to the contrary. On the other hand, sickness, infirmity, unwieldiness, pain of body, as well as all the external inconveniencies which tended to occasion or bring on any of them, poverty, the want of authority, the contempt or hatred of those we live with; were, in the same manner, pointed out to us as things to be shunned and avoided. In each of those two different classes of objects there were some which appeared to be more the objects either of choice or rejection than others in the same class. Thus, in the first class, health appeared evidently preferable to strength, and strength to agility; reputation to power, and power to riches. And thus too, in the second class, sickness was more to be avoided than unwieldiness of body, ignominy than poverty, and poverty than the want of authority. Virtue and the propriety of conduct consisted in choosing and rejecting all different objects and