It was Arthur Schopenhauer who said, "Religion has always been and always will be in conflict with the noble endeavor after pure truth."

Even the “Catholic Encyclopedia” admits, "His attitude of mind towards religious truth was that of a rationalist." To Bruno it would have been easier for him to change his sex than to change his mind.

"The spirit of dogmatic theology poisons everything it touches," said Bentham. "There is no pestilence in a state like a zeal for religion, independent of morality."

"Religion," Rand noted, "is the first enemy of the ability to think. ...yet before they learn to think [men] are discouraged by being ordered to take things on faith. Faith is the worst curse of mankind."

Comte denies metaphysics in favor of a reliance on sense experience as the source of human knowledge and denies the existence of a personal God.

"I cannot be angry at God, in whom I do not believe," De Beauvoir said.

"Fear prophets and those prepared to die for the truth," says Eco, "for as a rule they make many others die with them, often before them, at times instead of them."

Cicero may have adopted only a public profession of belief in immortality. “On the Nature of the Gods” gives the arguments for and against, but like a politician he takes neither side.

"As a set of cognitive beliefs, religion is a speculative hypothesis of low order of probability."

"Christianity persecuted, tortured, and burned. Like a hound it tracked the very scent of heresy. It kindled wars, and nursed furious hatreds and ambitions. It sanctified, quite like Mohammedanism, extermination and tyranny."