The greater the doubt, the greater the awakening

It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing - a somewhat unfamiliar conception for the average mind. Furthermore, the equation E = mc², in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa.

My internal and external life depend so much on the work of others that I must make an extreme effort to give as much as I receive.

The trouble with the younger generation is that they don't stay young for very long.

Considered logically this concept is not identical with the totality of sense impressions referred to; but it is an arbitrary creation of the human (or animal) mind.

I want to go when I want. It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly.

It is certainly true that principles cannot be more securely founded than on experience and consciously clear thinking.