It is vain for the sober man to knock at poesy's door.

As long as I draw breath and am able, I won't give up practicing philosophy.

Of all the animals, the boy is the most unmanageable, inasmuch as he has the fountain of reason in him not yet regulated.

Injustice is censured because the censures are afraid of suffering, and not from any fear which they have of doing injustice.

For a man to conquer himself is the first and noblest of all victories... The first and greatest victory is to conquer yourself; to be conquered by yourself is of all things most shameful and vile.

Prefer diligence before idleness, unless you esteem rust above brightness.

When the mind's eye rests on objects illuminated by truth and reality, it understands and comprehends them, and functions intelligently; but when it turns to the twilight world of change and decay, it can only form opinions, its vision is confused and its beliefs shifting, and it seems to lack intelligence.