13 Again, whoever may put to you the questions which you have propounded to us, let him understand that, under the guidance of deeper erudition and greater wisdom, you are ignorant of things like these. For if Themistocles regarded it as a small matter that he was looked upon as imperfectly educated when he had declined to play on the lyre at a banquet, and at the same time, when, after he had confessed ignorance of this accomplishment, one said, “What, then, do you know?” gave as his reply, “The art of making a small republic great”— are you to hesitate about admitting ignorance in trifles like these, when it is in your power to answer any one who may ask, “What, then, do you know?”— “The secret by which without such knowledge a man may be blessed”? And if you do not yet possess this secret, you act in searching into those other matters with as blind perversity as if, when labouring under some dangerous disease of the body, you eagerly sought after dainties in food and finery in dress, instead of physic and physicians. For this attainment ought not to be put off upon any pretext whatever, and no other knowledge ought, especially in our age, to receive a prior place in your studies. And now see how easily you may have this knowledge if you desire it. He who inquires how he may attain a blessed life is assuredly inquiring after nothing else than this: where is the highest good? In other words, wherein resides man's supreme good, not according to the perverted and hasty opinions of men, but according to the sure and immovable truth? Now its residence is not found by any one except in the body, or in the mind, or in God, or in two of these, or in the three combined. If, then, you have learned that neither the supreme good nor any part whatever of the supreme good is in the body, the remaining alternatives are, that it is in the mind, or in God, or in both combined. And if now you have also learned that what is true of the body in this respect is equally true of the mind, what now remains but God Himself as the One in whom resides man's supreme good?— not that there are no other goods, but that good is called the supreme good to which all others are related. For every one is blessed when he enjoys that for the sake of which he desires to have all other things, seeing that it is loved for its own sake, and not on account of something else. And the supreme good is said to be there because at this point nothing is found towards which the supreme good can go forth, or to which it is related. In it is the resting-place of desire; in it is assured fruition; in it the most tranquil satisfaction of a will morally perfect.
14. Give me a man who sees at once that the body is not the good of the mind, but that the mind is rather the good of the body: with such a man we would, of course, forbear from inquiring whether the highest good of which we speak, or any part of it, is in the body. For that the mind is better than the body is a truth which it would be utter folly to deny. Equally absurd would it be to deny that that which gives a happy life, or any part of a happy life, is better than that which receives the boon. The mind, therefore, does not receive from the body either the supreme good or any part of the supreme good. Men who do not see this have been blinded by that sweetness of carnal pleasures which they do not discern to be a consequence of imperfect health. Now, perfect health of body shall be the consummation of the immortality of the whole man. For God has endowed the soul with a nature so powerful, that from that consummate fullness of joy which is promised to the saints in the end of time, some portion overflows also upon the lower part of our nature, the body—not the blessedness which is proper to the part which enjoys and understands, but the plenitude of health, that is, the vigour of incorruption. Men who, as I have said, do not see this war with each other in unsatisfactory debates, each maintaining the view which may please his own fancy, but all placing the supreme good of man in the body, and so stir up crowds of disorderly carnal minds, of whom the Epicureans have flourished in pre-eminent estimation with the unlearned multitude.
15. Give me a man who sees at once, moreover, that when the mind is happy, it is happy not by good which belongs to itself, else it would never be unhappy: and with such a man we would, of course, forbear from inquiring whether that highest and, so to speak, bliss-bestowing good, or any part of it, is in the mind. For when the mind is elated with joy in itself, as if in good which belongs to itself, it is proud. But when the mind perceives itself to be mutable—a fact which may be learned from this, even though nothing else proved it, that the mind from being foolish may be made wise—and apprehends that wisdom is unchangeable, it must at the same time apprehend that wisdom is superior to its own nature, and that it finds more abundant and abiding joy in the communications and light of wisdom than in itself. Thus desisting and subsiding from boasting and self-conceit, it strives to cling to God, and to be recruited and reformed by Him who is unchangeable; whom it now understands to be the Author not only of every species of all things with which it comes in contact, either by the bodily senses or by intellectual faculties, but also of even the very capacity of taking form before any form has been taken, since the formless is defined to be that which can receive a form. Therefore it feels its own instability more, just in proportion as it clings less to God, whose being is perfect: it discerns also that the perfection of His being is consummate because He is immutable, and therefore neither gains nor loses, but that in itself every change by which it gains capacity for perfect clinging to God is advantageous, but every change by which it loses is pernicious, and further, that all loss tends towards destruction; and although it is not manifest whether any thing is ultimately destroyed, it is manifest to every one that the loss brings destruction so far that the object no longer is what it was. Whence the mind infers that the one reason why things suffer loss, or are liable to suffer loss, is, that they were made out of nothing; so that their property of being, and of permanence, and the arrangement whereby each finds even according to its imperfections its own place in the complex whole, all depend on the goodness and omnipotence of Him whose being is perfect, and who is the Creator able to make out of nothing not only something, but something great; and that the first sin, i.e. the first voluntary loss, is rejoicing in its own power: for it rejoices in something less than would be the source of its joy if it rejoiced in the power of God, which is unquestionably greater. Not perceiving this, and looking only to the capacities of the human mind, and the great beauty of its achievements in word and deed, some, who would have been ashamed to place man's supreme good in the body, have, by placing it in the mind, assigned to it unquestionably a lower sphere than that assigned to it by unsophisticated reason. Among Greek philosophers who hold these views, the chief place both in number of adherents and in subtlety of disputation has been held by the Stoics, who have, however, in consequence of their opinion that in nature everything is material, succeeded in turning the mind rather from carnal than material objects.
Source: Letters (New Advent)