Martyrdom, as a rule, establishes the sincerity of the martyr, never the correctness of his thought. Things are true or false in themselves.

When the will defies fear, when duty throws the gauntlet down to fate, when honor scorns to compromise with death - that is heroism.

Christianity did not come with tidings of great joy, but with a message of eternal grief. It came with the threat of everlasting torture on its lips. It meant war on earth and perdition hereafter.

Mental slavery is mental death, and every man who has given up his intellectual freedom is the living coffin of his dead soul.

When I became convinced that the universe is natural, that all the ghosts and gods are myths, there entered into my brain, into my soul, into every drop of my blood the sense, the feeling, the joy of freedom. The walls of my prison crumbled and fell. The dungeon was flooded with light and all the bolts and bars and manacles became dust.

A fact never went into partnership with a miracle. Truth scorns the assistance of wonders. A fact will fit every other fact in the universe, and that is how you can tell whether it is or is not a fact. A lie will not fit anything except another lie.

Blasphemy is what an old dogma screams at a new truth.