Quotes

When a man craves to acquire wealth ignobly, or feels no qualms in so acquiring it, he does not then by his gifts pay honor to his soul - far from it, forsooth!

- Plato, "Laws"

Why, what esle can I, a lame old man, do but sing hymns to God?  If, indeed, I were a nightingale, I should be singing as a nightingale; if a swan, as a swan.  But as it is, I am a rational being, therefore, I must be singing hymns of praise to God.

- Epictetus, "Discourses" 

(This is my favorite of the quotes I've listed so far)

Beng mortal, never pray for an untroubled life.  Rather, ask the gods to give you an enduring heart.

- Menander, fragment

(My mother had a poster on the wall of her office when I was a child.  It was the ocean crashing against some rocks, and it said, "Do not pray for an easy life.  Pray to be a strong person.")

Practice is everything.

- Periander, as quoted by Diogenes Laertius in "Lives and Opinions of Eminent Philosophers"

It will not always be summer; build barns.

-Hesiod, "Works and Days"

Eureka!

-Plutarch

The primary classes of men are these:  the philosopher or lover of wisdom, the lover of victory, and the lover of gain.

-Plato, "The Republic"

Of what use is a philosopher who doesn't hurt anybody's feelings?  

-Diogenes of Sinope, fragment

The people always have some champion whom they set over them and nurse into greatness...  This and no other is the root from which a tyrant springs; when he first appears as he is a protector.

- Socrates, as quoted in Plato's "The Republic"