The one exclusive sign of thorough knowledge is the power of teaching.

Of the irrational part of the soul again one division appears to be common to all living things, and of a vegetative nature.

For imagining lies within our power whenever we wish . . . but in forming opinons we are not free . . .

Man is a goal-seeking animal. His life only has meaning if he is reaching out and striving for his goals.

Two characteristic marks have above all others been recognized as distinguishing that which has soul in it from that which has not - movement and sensation.

In the perfect state the good man is absolutely the same as the good citizen; whereas in other states the good citizen is only good relatively to his own form of government.

Greatness of spirit is to bear finely both good fourtune and bad, honor and disgrace, and not to think highly of luxury or attention or power or victories in contests, and to possess a certain depth and magnitude of spirit.