1. It is a useful fact that you wish to know, one which is essential to him who hastens after wisdom – namely, the parts of philosophy and the division of its huge bulk into separate members. For by studying the parts we can be brought more easily to understand the whole. I only wish that philosophy might come before our eyes in all her unity, just as the whole expanse of the firmament is spread out for us to gaze upon! It would be a sight closely resembling that of the firmament. For then surely philosophy would ravish all mortals with love for her; we should abandon all those things which, in our ignorance of what is great, we believe to be great. Inasmuch, however, as this cannot fall to our lot, we must view philosophy just as men gaze upon the secrets of the firmament.

2. The wise man's mind, to be sure, embraces the whole framework of philosophy, surveying it with no less rapid glance than our mortal eyes survey the heavens; we, however, who must break through the gloom, we whose vision fails even for that which is near at hand, can be shown with greater ease each separate object even though we cannot yet comprehend the universe. I shall therefore comply with your demand, and shall divide philosophy into parts, but not into scraps. For it is useful that philosophy should be divided, but not chopped into bits. Just as it is hard to take in what is indefinitely large, so it is hard to take in what is indefinitely small. 3. The people are divided into tribes, the army into centuries. Whatever has grown to greater size is more easily identified if it is broken up into parts; but the parts, as I have remarked, must not be countless in number and diminutive in size. For over-analysis is faulty in precisely the same way as no analysis at all; whatever you cut so fine that it becomes dust is as good as blended into a mass again.

4. In the first place, therefore, if you approve, I shall draw the distinction between wisdom and philosophy. Wisdom is the perfect good of the human mind; philosophy is the love of wisdom, and the endeavour to attain it. The latter strives toward the goal which the former has already reached. And it is clear why philosophy was so called. For it acknowledges by its very name the object of its love. 5. Certain persons have defined wisdom as the knowledge of things divine and things human. Still others say: "Wisdom is knowing things divine and things human, and their causes also." This added phrase seems to me to be superfluous, since the causes of things divine and things human are a part of the divine system. Philosophy also has been defined in various ways; some have called it "the study of virtue," others have referred to it as "a study of the way to amend the mind," and some have named it "the search for right reason." 6. One thing is practically settled, that there is some difference between philosophy and wisdom. Nor indeed is it possible that that which is sought and that which seeks are identical. As there is a great difference between avarice and wealth, the one being the subject of the craving and the other its object, so between philosophy and wisdom. For the one is a result and a reward of the other. Philosophy does the going, and wisdom is the goal. 7. Wisdom is that which the Greeks call σοφία. The Romans also were wont to use this word in the sense in which they now use "philosophy" also. This will be proved to your satisfaction by our old national plays, as well as by the epitaph that is carved on the tomb of Dossennus:

Pause, stranger, and read the wisdom of Dossennus.

8. Certain of our school, however, although philosophy meant to them "the study of virtue," and though virtue was the object sought and philosophy the seeker, have maintained nevertheless that the two cannot be sundered. For philosophy cannot exist without virtue, nor virtue without philosophy. Philosophy is the study of virtue, by means, however, of virtue itself; but neither can virtue exist without the study of itself, nor can the study of virtue exist without virtue itself. For it is not like trying to hit a target at long range, where the shooter and the object to be shot at are in different places. Nor, as roads which lead into a city, are the approaches to virtue situated outside virtue herself; the path by which one reaches virtue leads by way of virtue herself; philosophy and virtue cling closely together.

9. The greatest authors, and the greatest number of authors, have maintained that there are three divisions of philosophy – moral, natural, and rational. The first keeps the soul in order; the second investigates the universe; the third works out the essential meanings of words, their combinations, and the proofs which keep falsehood from creeping in and displacing truth. But there have also been those who divided philosophy on the one hand into fewer divisions, on the other hand into more. 10. Certain of the Peripatetic school have added a fourth division, "civil philosophy," because it calls for a special sphere of activity and is interested in a different subject matter. Some have added a department for which they use the Greek term "economics," the science of managing one's own household. Still others have made a distinct heading for the various kinds of life. There is no one of these subdivisions, however, which will not be found under the branch called "moral" philosophy.

11. The Epicureans held that philosophy was twofold, natural and moral; they did away with the rational branch. Then, when they were compelled by the facts themselves to distinguish between equivocal ideas and to expose fallacies that lay hidden under the cloak of truth, they themselves also introduced a heading to which they give the name "forensic and regulative," which is merely "rational" under another name, although they hold that this section is accessory to the department of "natural" philosophy. 12. The Cyrenaic school abolished the natural as well as the rational department, and were content with the moral side alone; and yet these philosophers also include under another title that which they have rejected. For they divide moral philosophy into five parts: (1) What to avoid and what to seek, (2) The Passions, (3) Actions, (4) Causes, (5) Proofs. Now the causes of things really belong to the "natural" division, the proofs to the "rational." 13. Aristo of Chios remarked that the natural and the rational were not only superfluous, but were also contradictory. He even limited the "moral," which was all that was left to him; for he abolished that heading which embraced advice, maintaining that it was the business of the pedagogue, and not of the philosopher – as if the wise man were anything else than the pedagogue of the human race!

14. Since, therefore, philosophy is threefold, let us first begin to set in order the moral side. It has been agreed that this should be divided into three parts. First, we have the speculative part, which assigns to each thing its particular function and weighs the worth of each; it is highest in point of utility. For what is so indispensable as giving to everything its proper value? The second has to do with impulse, the third with actions. For the first duty is to determine severally what things are worth; the second, to conceive with regard to them a regulated and ordered impulse; the third, to make your impulse and your actions harmonize, so that under all these conditions you may be consistent with yourself. 15. If any of these three be defective, there is confusion in the rest also. For what benefit is there in having all things appraised, each in its proper relations, if you go to excess in your impulses? What benefit is there in having checked your impulses and in having your desires in your own control, if when you come to action you are unaware of the proper times and seasons, and if you do not know when, where, and how each action should be carried out? It is one thing to understand the merits and the values of facts, another thing to know the precise moment for action, and still another to curb impulses and to proceed, instead of rushing, toward what is to be done. Hence life is in harmony with itself only when action has not deserted impulse, and when impulse toward an object arises in each case from the worth of the object, being languid or more eager as the case may be, according as the objects which arouse it are worth seeking.

16. The natural side of philosophy is twofold: bodily and non-bodily. Each is divided into its own grades of importance, so to speak. The topic concerning bodies deals, first, with these two grades: the creative and the created; and the created things are the elements. Now this very topic of the elements, as some writers hold, is integral; as others hold, it is divided into matter, the cause which moves all things, and the elements.

17. It remains for me to divide rational philosophy into its parts. Now all speech is either continuous, or split up between questioner and answerer. It has been agreed upon that the former should be called rhetoric, and the latter dialectic. Rhetoric deals with words, and meanings, and arrangement. Dialectic is divided into two parts: words and their meanings, that is, into things which are said, and the words in which they are said. Then comes a subdivision of each – and it is of vast extent. Therefore I shall stop at this point, and

But treat the climax of the story;

for if I should take a fancy to give the subdivisions, my letter would become a debater's handbook! 18. I am not trying to discourage you, excellent Lucilius, from reading on this subject, provided only that you promptly relate to conduct all that you have read.

It is your conduct that you must hold in check; you must rouse what is languid in you, bind fast what has become relaxed, conquer what is obstinate, persecute your appetites, and the appetites of mankind, as much as you can; and to those who say: "How long will this unending talk go on?" answer with the words: 19. "I ought to be asking you 'How long will these unending sins of yours go on?'" Do you really desire my remedies to stop before your vices? But I shall speak of my remedies all the more, and just because you offer objections I shall keep on talking. Medicine begins to do good at the time when a touch makes the diseased body tingle with pain. I shall utter words that will help men even against their will. At times you should allow words other than compliments to reach your ears, and because as individuals you are unwilling to hear the truth, hear it collectively. 20. How far will you extend the boundaries of your estates? An estate which held a nation is too narrow for a single lord. How far will you push forward your ploughed fields – you who are not content to confine the measure of your farms even within the amplitude of provinces? You have noble rivers flowing down through your private grounds; you have mighty streams – boundaries of mighty nations – under your dominion from source to outlet. This also is too little for you unless you also surround whole seas with your estates, unless your steward holds sway on the other side of the Adriatic, the Ionian, and the Aegean seas, unless the islands, homes of famous chieftains, are reckoned by you as the most paltry of possessions! Spread them as widely as you will, if only you may have as a "farm" what was once called a kingdom; make whatever you can your own, provided only that it is more than your neighbour's!

21. And now for a word with you, whose luxury spreads itself out as widely as the greed of those to whom I have just referred. To you I say: "Will this custom continue until there is no lake over which the pinnacles of your country-houses do not tower? Until there is no river whose banks are not bordered by your lordly structures? Wherever hot waters shall gush forth in rills, there you will be causing new resorts of luxury to rise. Wherever the shore shall bend into a bay, there will you straightway be laying foundations, and, not content with any land that has not been made by art, you will bring the sea within your boundaries. On every side let your house-tops flash in the sun, now set on mountain peaks where they command an extensive outlook over sea and land, now lifted from the plain to the height of mountains; build your manifold structures, your huge piles, – you are nevertheless but individuals, and puny ones at that! What profit to you are your many bed-chambers? You sleep in one. No place is yours where you yourselves are not." 22. "Next I pass to you, you whose bottomless and insatiable maw explores on the one hand the seas, on the other the earth, with enormous toil hunting down your prey, now with hook, now with snare, now with nets of various kinds; no animal has peace except when you are cloyed with it. And how slight a portion of those banquets of yours, prepared for you by so many hands, do you taste with your pleasure-jaded palate! How slight a portion of all that game, whose taking was fraught with danger, does the master's sick and squeamish stomach relish? How slight a portion of all those shell-fish, imported from so far, slips down that insatiable gullet? Poor wretches, do you not know that your appetites are bigger than your bellies?"

23. Talk in this way to other men, – provided that while you talk you also listen; write in this way, – provided that while you write you read, remembering that everything you hear or read, is to be applied to conduct, and to the alleviation of passion's fury. Study, not in order to add anything to your knowledge, but to make your knowledge better. Farewell.