It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.

We had better dispense with the personification of evil, because it leads, all too easily, to the most dangerous kind of war: religious war.

Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.

One of the most dangerously vicious circles menacing the continued existence of all mankind arises through that grim striving for the highest possible position within the ranked order, in other words, the reckless pursuit of power which combines with an insatiable greed of neurotic proportions that the results of acquired power confer.

Evil, by definition, is that which endangers the good, and the good is that which we perceive as a value.

In nature we find not only that which is expedient, but also everything which is not so inexpedient as to endanger the existence of the species.

Scientific truth is universal, because it is only discovered by the human brain and not made by it, as art is.