The first step towards philosophy is incredulity.

To derive two or three general Principles of Motion from Phænomena, and afterwards to tell us how the Properties and Actions of all corporeal…

— Isaac Newton

Philosophy arises from an unusually obstinate attempt to arrive at real knowledge. What passes for knowledge in ordinary life suffers from three defects: it…

— Bertrand Russell

Scepticism is the first step toward truth.

— Denis Diderot

Knowledge of divine things for the most part is lost to us by incredulity.

— Heraclitus

Sometimes the fluffy bunny of incredulity zooms around the bend so rapidly that the greyhound of language is left, agog, in the starting cage.

— David Mitchell

“Jules turned to her, incredulous. 'Do you socialize with Republicans?' "'It happens, Jules.”

— Jennifer Egan

The human understanding is a revelation from its maker, which can never be disputed or doubted. There can be no scepticism, Pyrrhonism, or incredulity…

— John Adams

Of all the weaknesses little men rail against, there is none that they are more apt to ridicule than the tendency to believe. And…

— Edward Bulwer-Lytton, 1st Baron Lytton

The Bishop goes on to the human eye, asking rhetorically, and with the implication that there is no answer, 'How could an organ so…

— Richard Dawkins

... [a] girl one day flared out and told the principal "the only mission opening before a girl in his school was to marry…

— Anna Julia Cooper

We are responsible for our incredulity.

— Samantha Power

“The theologian Meric Casaubon argued—in his 1668 book, Of Credulity and Incredulity—that witches must exist because, after all, everyone believes in them. Anything that…

— Carl Sagan

“If you can't show it, you don't know it.”

— Aron Ra

The reformer has enemies in all who profit by the old order, and only lukewarm defenders in all those who would profit by the…

— Niccolo Machiavelli

Looking back through the mists of time, I recall some distinctly religious experiences in my teens--when I was only fourteen years old to be…

— Andrew Linzey