text: Now let us turn to a consideration of the virtues. Some persons will advise us to rate prudence very high, to cherish bravery, and to cleave more closely, if possible, to justice than to all other qualities. But this will do us no good if we do not know what virtue is, whether it is simple or compound, whether it is one or more than one, whether its parts are separate or interwoven with one another; whether he who has one virtue possesses the other virtues also; and just what are the distinctions between them. The carpenter does not need to inquire about his art in the light of its origin or of its function, any more than a pantomime need inquire about the art of dancing; if these arts understand themselves, nothing is lacking, for they do not refer to life as a whole. But virtue means the knowledge of other things besides herself: if we would learn virtue we must learn all about virtue. Conduct will not be right unless the will to act is right; for this is the source of conduct. Nor, again, can the will be right without a right attitude of mind; for this is the source of the will. Furthermore, such an attitude of mind will not be found even in the best of men unless he has learned the laws of life as a whole and has worked out a proper judgment about everything, and unless he has reduced facts to a standard of truth. Peace of mind is enjoyed only by those who have attained a fixed and unchanging standard of judgment; the rest of mankind continually ebb and flow in their decisions, floating in a condition where they alternately reject things and seek them. And what is the reason for this tossing to and fro? It is because nothing is clear to them, because they make use of a most unsure criterion – rumour. If you would always desire the same things, you must desire the truth. But one cannot attain the truth without doctrines; for doctrines embrace the whole of life. Things good and evil, honourable and disgraceful, just and unjust, dutiful and undutiful, the virtues and their practice, the possession of comforts, worth and respect, health, strength, beauty, keenness of the senses – all these qualities call for one who is able to appraise them. One should be allowed to know at what value every object is to be rated on the list; for sometimes you are deceived and believe that certain things are worth more than their real value; in fact, so badly are you deceived that you will find you should value at a mere pennyworth those things which we men regard as worth most of all – for example, riches, influence, and power.