Robert G. Ingersoll

The sciences are not sectarian. People do not persecute each other on account of disagreements in mathematics. Families are not divided about botany and astronomy does not even tend to make a man hate his father and mother. It is what people do not know that they persecute each other about. Science will bring, not a sword, but peace.

— Robert G. Ingersoll

H. L. Mencken

To sum up:
1. The cosmos is a gigantic flywheel making 10,000 revolutions a minute.
2. Man is a sick fly taking a dizzy ride on it.
3. Religion is the theory that the wheel was designed and set spinning to give him a ride.

— H. L. Mencken
Mencken, H.L. (1920). "Coda". Smart Set, December.

Cardinal Robert Bellarmine

To assert that the earth revolves around the sun is as erroneous as to claim that Jesus was not born of a virgin.

— Cardinal Robert Bellarmine
Trial of Galileo, 1615

Karen Armstrong

My neurologist once told me that people with temporal lobe epilepsy are very often intensely religious. Certainly just before I have a grand mal fit I have a ‘vision’ of such peace, joy and significance that I can only call it God. What does this say about the whole nature of religious vision? Certain episodes in the lives of the saints have acquired a new meaning for me. When Theresa of Avila had her three-day vision of hell, was she simply having a temporal lobe attack? The horrors she saw are similar to those I have experienced, but in her case informed by the religious imagery of her time. Like other saints who have ‘seen’ hell she describes an appalling stench, which is part of an epileptic aura. Is it possible that the feeling I have had all my life that something – God, perhaps? – is just over the horizon, something unimaginable but almost tangibly present, is simply the result of an electrical irregularity in my brain? It is a question that can’t yet be answered, unless it be that God, if He exists, could have created us with that capacity for Him, glimpsed at only when the brain is convulsed. What I can say, however, is that if my ‘visions’ have sometimes let me into ‘Hell’ they have also given me possible intimations of a Heaven which I would not have been without.

— Karen Armstrong
Armstrong, K. (1983). Beginning the World. New York: St Martin's Press.

Bertrand Russell

Conventional people are roused to fury by departure from convention, largely because they regard such departure as a criticism of themselves.

— Bertrand Russell
Russell, B. (1996). The Conquest of Happiness. New York: Liveright.