What is the chief good must be an object of inquiry, that our whole life and actions may be directed to it. When inquiry is made respecting the chief good of man, it ought to be settled to be of such a kind, first, that it have reference to man alone; in the next place, that it belong peculiarly to the mind; lastly, that it be sought by virtue. Let us see, therefore, whether the chief good which the philosophers mark out be such that it has reference neither to a dumb animal nor to the body, and cannot be attained without virtue.
Aristippus, the founder of the Cyrenaic sect, who thought that bodily pleasure was the chief good, ought to be removed from the number of philosophers, and from the society of men, because he compared himself to a beast. The chief good of Hieronymus is to be without pain, that of Diodorus to cease to be in pain. But the other animals avoid pain; and when they are without pain, or cease to be in pain, are glad. What distinction, then, will be given to man, if his chief good is judged to be common with the beasts? Zeno thought that the chief good was to live agreeably to nature. But this definition is a general one. For all animals live agreeably to nature, and each has its own nature.
Epicurus maintained that it was pleasure of the soul. What is pleasure of the soul but joy, in which the soul for the most part luxuriates, and unbends itself either to sport or to laughter? But this good befalls even dumb animals, which, when they are satisfied with pasture, relax themselves to joy and wantonness. Dinomachus and Callipho approved of honourable pleasure; but they either said the same that Epicurus did, that bodily pleasure is dishonourable; or if they considered bodily pleasures to be partly base and partly honourable, then that is not the chief good which is ascribed to the body. The Peripatetics make up the chief good of goods of the soul, and body, and fortune. The goods of the soul may be approved of; but if they require assistance for the completion of happiness, they are plainly weak. But the goods of the body and of fortune are not in the power of man; nor is that now the chief good which is assigned to the body, or to things placed without us, because this double good extends even to the cattle, which have need of being well, and of a due supply of food. The Stoics are believed to have entertained much better views, who said that virtue was the chief good. But virtue cannot be the chief good, since, if it is the endurance of evils and of labours, it is not happy of itself; but it ought to effect and produce the chief good, because it cannot be attained without the greatest difficulty and labour. But, in truth, Aristotle wandered far from reason, who connected honour with virtue, as though it were possible for virtue at any time to be separated from honour, or to be united with baseness.
Herillus the Pyrrhonist made knowledge the chief good. This indeed belongs to man, and to the soul only, but it may happen to him without virtue. For he is not to be considered happy who has either learnt anything by hearing, or has gained the knowledge of it by a little reading; nor is it a definition of the chief good, because there may be a knowledge either of bad things, or at any rate of things that are useless. And if it is the knowledge of good and useful things which you have acquired by labour, nevertheless it is not the chief good, because knowledge is p. 235 not sought on its own account, but on account of something else. For the arts are learnt on this account, that they may be to us the means of gaining support, or a source of glory, or even of pleasure; and it is plain that these things cannot be the chief goods. Therefore the philosophers do not observe the rule even in moral philosophy, inasmuch as they are at variance with one another on the main point 1495 itself, that is, in that discussion by which the life is moulded. For the precepts cannot be equal, or resembling one another, when some train men to pleasure, others to honour, others indeed to nature, others to knowledge; some to the pursuit, others to the avoiding of riches; some to entire insensibility to pain, others to the endurance of evils: in all which, as I have shown before, they turn aside from reason, because they are ignorant of God.
In ipso cardine. [Horace, Sat., book ii. 6, 71–76.]