The race of the guardians must be kept pure.

There will be no end to the troubles of states,Or of humanity itself,Till philosophers become kings in this world,Or till those we now call kings and rulers really And truly become philosophers

He who is not a good servant will not be a good master.

If there is a good and wise God, then there also exists a progress of humanity toward perfection.

The true lover of knowledge naturally strives for truth, and is not content with common opinion, but soars with undimmed and unwearied passion till he grasps the essential nature of things.

Ignorance is the root cause of all difficulties.

Knowledge becomes evil if the aim be not virtuous.