To leave the number of births unrestricted, as is done in most states, inevitably causes poverty among the citizens, and poverty produces crime and faction.
Of ill-temper there are three kinds: irascibility, bitterness, sullenness. It belongs to the ill-tempered man to be unable to bear either small slights or defeats but to be given to retaliation and revenge, and easily moved to anger by any chance deed or word. Ill-temper is accompanied by excitability of character, instability, bitter speech, and liability to take offence at trifles and to feel these feelings quickly and on slight occasions.
All men naturally desire knowledge. An indication of this is our esteem for the senses; for apart from their use we esteem them for their own sake, and most of all the sense of sight. Not only with a view to action, but even when no action is contemplated, we prefer sight, generally speaking, to all the other senses. The reason of this is that of all the senses sight best helps us to know things, and reveals many distinctions.
Even if we could suppose the citizen body to be virtuous, without each of them being so, yet the latter would be better, for in the virtue of each the virtue of all is involved.