Man can be scientifically manipulated.

The conception of the necessary unit of all that is resolves itself into the poverty of the imagination, and a freer logic emancipates us from the straitwaistcoated benevolent institution, which idealism palms off as the totality of being.

All the labor of all the ages, all the devotion, all the inspiration, all the noonday brightness of human genius are destined to extinction. So now, my friends, if that is true, and it is true, what is the point?

Most of the greatest evils that man has inflicted upon man have come through people feeling quite certain about something which, in fact, was false.

It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition.

I am allowed to use plain English because everybody knows that I could use mathematical logic if I chose.

One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision.