Firmness in decision is often merely a form of stupidity. It indicates an inability to think the same thing out twice.

the average man does not want to be free. he simply wants to be safe.

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.

The ideal state for a philosopher, indeed, is celibacy tempered by polygamy.

The taboos that I have mentioned are extraordinarily harsh and numerous. They stand around nearly every subject that is genuinely important to man: they hedge in free opinion and experimentation on all sides. Consider, for example, the matter of religion. It is debated freely and furiously in almost every country in the world save the United States, but here the critic is silenced. The result is that all religions are equally safeguarded against criticism, and that all of them lose vitality. We protect the status quo, and so make steady war upon revision and improvement.

The final test of truth is ridicule. Very few dogmas have ever faced it and survived.

The truth is that the scientific value of Polar exploration is greatly exaggerated. The thing that takes men on such hazardous trips is really not any thirst for knowledge, but simply a yearning for adventure. ... A Polar explorer always talks grandly of sacrificing his fingers and toes to science. It is an amiable pretention, but there is no need to take it seriously.