“Gravity is not a version of the truth. It is the truth. Anyone who doubts it is invited to jump out a tenth-storey window.”

“It is a simple logic truth that, short of mass emigration into space, with rockets taking off at the rate of several million per second, uncontrolled birth-rates are bound to lead to horribly increased death –rates. It is hard to believe that this simple truth is not understood by those leaders who forbid their followers to use effective contraceptive methods. They express a preference for ‘natural’ methods of population limitation, and a natural method is exactly what they are going to get. It is called starvation.”

“It is hard to believe that this simple truth is not understood by those leaders who forbid their followers to use effective contraceptive methods. They express a preference for 'natural' methods of population limitation, and a natural method is exactly what they are going to get. It is called starvation.”

“Religion is about turning untested belief into unshakable truth through the power of institutions and the passage of time.”

“We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes. This is a truth which still fills me with astonishment.”

“...when two opposite points of view are expressed with equal intensity, the truth does not necessarily lie exactly halfway between them. It is possible for one side to be simply wrong.”

“If the history-deniers who doubt the fact of evolution are ignorant of biology, those who think the world began less than ten thousand years ago are worst than ignorant, they are the deluded to the point of perversity.”