The first and most necessary topic in philosophy is that of the use of moral theorems, such as, "We ought not to lie;" the second is that of demonstrations, such as, "What is the origin of our obligation not to lie;" the third gives strength and articulation to the other two, such as, "What is the origin of this is a demonstration." For what is demonstration? What is consequence? What contradiction? What truth? What falsehood? The third topic, then, is necessary on the account of the second, and the second on the account of the first. But the most necessary, and that whereon we ought to rest, is the first. But we act just on the contrary. For we spend all our time on the third topic, and employ all our diligence about that, and entirely neglect the first. (51).
Whatever moral rules you have deliberately proposed to yourself abide by them as they were laws, and as if you would be guilty of impiety by violating any of them. Don't regard what anyone says of you, for this, after all, is no concern of yours. How long, then, will you put off thinking yourself worthy of the highest improvements and follow the distinctions of reason? You have received the philosophical theorems, with which you ought to be familiar, and you have been familiar with them. What other master, then, do you wait for, to throw upon that the delay of reforming yourself?... Let whatever appears to be the best be to you an inviolable law.(50).
Never call yourself a philosopher, nor talk a great deal among the unlearned about theorems, but act conformably to them. Thus, at an entertainment, don't talk how persons ought to eat, but eat as you ought. For remember that in this manner Socrates also universally avoided all ostentation. And when persons came to him and desired to be recommended by him to philosophers, he took and recommended them, so well did he bear being overlooked. So that if ever any talk should happen among the unlearned concerning philosophic theorems, be you, for the most part, silent. For there is great danger in immediately throwing out what you have not digested. And, if anyone tells you that you know nothing, and you are not nettled at it, then you may be sure that you have begun your business. For sheep don't throw up the grass to show the shepherds how much they have eaten; but, inwardly digesting their food, they outwardly produce wool and milk. Thus, therefore, do you likewise not show theorems to the unlearned, but the actions produced by them after they have been digested. (46).
Does anyone bathe in a mighty little time? Don't say that he does it ill, but in a mighty little time. Does anyone drink a great quantity of wine? Don't say that he does ill, but that he drinks a great quantity. For, unless you perfectly understand the principle from which anyone acts, how should you know if he acts ill? Thus you will not run the hazard of assenting to any appearances but such as you fully comprehend. (45).
These reasonings are unconnected: "I am richer than you, therefore I am better"; "I am more eloquent than you, therefore I am better." The connection is rather this: "I am richer than you, therefore my property is greater than yours;" "I am more eloquent than you, therefore my style is better than yours." But you, after all, are neither property nor style.
Everything has two handles, the one by which it may be carried, the other by which it cannot. If your brother acts unjustly, don't lay hold on the action by the handle of his injustice, for by that it cannot be carried; but by the opposite, that he is your brother, that he was brought up with you; and thus you will lay hold on it, as it is to be carried. (43).
When you do anything from a clear judgment that it ought to be done, never shun the being seen to do it, even though the world should make a wrong supposition about it; for, if you don't act right, shun the action itself; but, if you do, why are you afraid of those who censure you wrongly? (35).
If a man has reported to you, that a certain person speaks ill of you, do not make any defense (answer) to what has been told you: but reply, The man did not know the rest of my faults, for he would not have mentioned these only.
If a person gave your body to any stranger he met on his way, you would certainly be angry. And do you feel no shame in handing over your own mind to be confused and mystified by anyone who happens to verbally attack you? (28) [tr. Elizabeth Carter]