Of Happiness

Happiness is that state of consciousness which proceeds from the achievement of one's values...[and]
...the achievement of your happiness is the only moral purpose of your life, and that happiness—not pain or mindless self-indulgence—is the proof of your moral integrity, since it is the proof and the result of your loyalty to the achievement of your values.

[T]here is no more despicable coward than the man who deserted the battle for his joy, fearing to assert his right to existence, lacking the courage and the loyalty to life of a bird or a flower reaching for the sun. Discard the protective rags of that vice which you called a virtue: humility—learn to value yourself, which means: to fight for your happiness—and when you learn that prideis the sum of all virtues, you will learn to live like a man.

Ayn Rand, Atlas Shrugged