Darwin has done more to change human thought than all the priests who have existed.

Every child should be taught that useful work is worship and that intelligent labor is the highest form of prayer.

The intellectual advancement of man depends on how often he can exchange an old superstition for a new truth.

The first step is for man to cease to be the slave of man. The second, is to cease to be the slave of the monsters of his own creation, the ghosts and phantoms of the air.

Commerce is the great civilizer. We exchange ideas when we exchange fabrics.

I hate above all things a cross man. What right has he to murder the sunshine of a day? What right has he to assassinate the Joy of life? When you go home, you ought to go like a ray of light-so that it will, even in the night, burst out of the doors and windows and illuminate the darkness.

Let us put theology out of religion. Theology has always sent the worst to heaven, the best to hell.