Knowledge is happiness, because to have knowledge - broad, deep knowledge - is to know true ends from false, and lofty things from low.
When it seems that our sorrow is too great to be borne, let us think of the great family of the heavy-hearted into which our grief has given us entrance. And inevitably, we will feel about us their arms, their sympathy and their understanding.
A man can't make a place for himself in the sun if he keeps taking refuge under the family tree.
The test of all beliefs is their practical effect in life. If it be true that optimism compels the world forward, and pessimism retards it, then it is dangerous to propagate a pessimistic philosophy.