Plato

Be kind, for everyone you meet is fighting a hard battle.

Ignorance, the root and the stem of every evil.

Man...is a tame or civilized animal; never the less, he requires proper instruction and a fortunate nature, and then of all animals he becomes the most divine and most civilized; but if he be insufficiently or ill- educated he is the most savage of earthly creatures.

The price good men pay for indifference to public affairs is to be ruled by evil men.

They certainly give very strange names to diseases.

Wise men talk because they have something to say; fools, because they have to say something.

You can discover more about a person in an hour of play than in a year of conversation.

False words are not only evil in themselves, but they infect the soul with evil.

The partisan, when he is engaged in a dispute, cares nothing about the rights of the question, but is anxious only to convince his hearers of his own assertions.

You are young, my son, and, as the years go by, time will change and even reverse many of your present opinions. Refrain therefore awhile from setting yourself up as a judge of the highest matters.

Everything that deceives may be said to enchant.

He who is of calm and happy nature will hardly feel the pressure of age, but to him who is of an opposite disposition youth and age are equally a burden.

I have hardly ever known a mathematician who was capable of reasoning.

Mankind censure injustice fearing that they may be the victims of it, and not because they shrink from committing it.

Necessity, who is the mother of invention.

The beginning is the most important part of the work.