A man who examines each subject from a philosophical standpoint cannot neglect them: he has to omit nothing, and state the truth about each topic.

My best friend is the man who in wishing me well wishes it for my sake.

A life of wealth and many belongings is only a means to happiness. Honor, power, and success cannot be happiness because they depend on the whims of others, and happiness should be self-contained, complete in itself.

It is the mark of an educated mind to expect that amount of exactness which the nature of the particular subject admits. It is equally unreasonable to accept merely probable conclusions from a mathematician and to demand strict demonstration from an orator.

He is his own best friend and takes delight in privacy whereas the man of no virtue or ability is his own worst enemy and is afraid of solitude.

The more you know, the more you know you don't know.

Since the whole city has one end, it is manifest that education should be one and the same for all, and that it should be public, and not private - not as at present, when every one looks after his own children separately, and gives them separate instruction of the sort which he thinks best; the training in things which are of common interest should be the same for all. Neither must we suppose that any one of the citizens belongs to himself, for they all belong to the state, and are each of them a part of the state, and the care of each part is inseparable from the care of the whole.