One should guard against preaching to young people success in the customary form as the main aim in life. The most important motive for work in school and in life is pleasure in work, pleasure in its result, and the knowledge of the value of the result to the community.
Science has gone a long way toward helping man to free himself from the burden of hard labor; yet, science itself is not a liberator. It creates means, not goals. It is up to men to utilize those means to achieve reasonable goals.
The conscientious objector is a revoultionary. On deciding to disobey the law he sacrifices his personal interests to the most important cause of working for the betterment of society.
When men are engaged in war and conquest, the tools of science become as dangerous as a razor in the hands of a child of three. We must not condemn man because his inventiveness and patient conquest of the forces of nature are being exploited for false and destructive purposes. Rather, we should remember that the fate of mankind hinges entirely upon man’s moral development.
Perfection of means and confusion of goals seem to characterize our age. If we desire sincerely and passionately the safety, the welfare and the free development of the talents of all men, we shall not be in want of the means to approach such a state.
If you want to find out anything from the theoretical physicists about the methods they use, I advise you to stick closely to one principle: don't listen to their words, fix your attention on their deeds. To him who is a discoverer in this field the products of his imagination appear so necessary and natural that he regards them, and would like to have them regarded by others, not as creations of thought but as given realities.