which are to them what the head and soul are to the living being.  ‘How do you mean?’ Mind in the soul, and sight and hearing in the head, or rather, the perfect union of mind and sense, may be justly called every man’s salvation.  ‘Certainly.’  Yes; but of what nature is this union?  In the case of a ship, for example, the senses of the sailors are added to the intelligence of the pilot, and the two together save the ship and the men in the ship.  Again, the physician and the general have their objects; and the object of the one is health, of the other victory.  States, too, have their objects, and the ruler must understand, first, their nature, and secondly, the means of attaining them, whether in laws or men.  The state which is wanting in this knowledge cannot be expected to be wise when the time for action arrives.  Now what class or institution is there in our state which has such a saving power?  ‘I suspect that you are referring to the Nocturnal Council.’  Yes, to that council which is to have all virtue, and which should aim directly at the mark.  ‘Very true.’  The inconsistency of legislation in most states is not surprising, when the variety of their objects is considered.  One of them makes their rule of justice the government of a class; another aims at wealth; another at freedom, or at freedom and power; and some who call themselves philosophers maintain that you should seek for all of them at once.  But our object is unmistakeably virtue, and virtue is of four kinds.  ’Yes; and we said that mind is the chief and ruler of the three other kinds of virtue and of all else.’  True, Cleinias; and now, having already declared the object which is present to the mind of the pilot, the general, the physician, we will interrogate the mind of the statesman.  Tell me, I say, as the physician and general have told us their object, what is the object of the statesman.  Can you tell me?  ‘We cannot.’  Did we not say that there are four virtues—­courage, wisdom, and two others, all of which are called by the common name of virtue, and are in a sense one?  ‘Certainly we did.’  The difficulty is, not in understanding the differences of the virtues, but in apprehending their unity.  Why do we call virtue, which is a single thing, by the two names of wisdom and courage?  The reason is that courage is concerned with fear, and is found both in children and in brutes; for the soul may be courageous without reason, but no soul was, or ever will be, wise without reason.  ’That is true.’  I have explained to you the difference, and do you in return explain to me the unity.  But first let us consider whether any one who knows the name of a thing without the definition has any real knowledge of it.  Is not such knowledge a disgrace to a man of sense, especially where great and glorious truths are concerned? and can any subject be more worthy of the attention of our legislators than the four virtues of which we are speaking—­courage, temperance, justice, wisdom?  Ought not the magistrates