The essence of science is that it is always willing to abandon a given idea, however fundamental it may seem to be, for a better one; the essence of theology is that it holds its truths to be eternal and immutable. To be sure, theology is always yielding a little to the progress of knowledge, and only a Holy Roller in the mountains of Tennessee would dare to preach today what the popes preached in the Thirteenth Century, but this yielding is always done grudgingly, and thus lingers a good while behind the event.

In the United States, doing good has come to be, like patriotism, a favorite device of persons with something to sell.

The chief knowledge that's man on from reading books is the knowledge that very few of them are worth reading.

Bridges would not be safer if only people who knew the proper definition of a real number were allowed to design them.

You can't do anything about the length of your life, but you can do something about its width and depth.

No professional politician is ever actually in favor of public economy. It is his implacable enemy, and he knows it. All professional politicians are dedicated wholeheartedly to waste and corruption. They are the enemies of every decent man.

I have little belief in human progress. The human race is incurably idiotic. It will never be happy.