It is easier to denature plutonium than to denature the evil spirit of man.

Democracy, taken in its narrower, purely political, sense, suffers from the fact that those in economic and political power possess the means for molding public opinion to serve their own class interests. The democratic form of government in itself does not automatically solve problems; it offers, however, a useful framework for their solution. Everything depends ultimately on the political and moral qualities of the citizenry.

Out yonder there is this huge world, which exists independently of us human beings and which stands before us like a great, eternal riddle, at least partially accessible to our inspection and thinking

It is important to foster individuality, for only the individual can produce the new ideas.

Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.

The grand aim of all science is to cover the greatest number of empirical facts by logical deduction from the smallest number of hypotheses or axioms.

The wireless telegraph is not difficult to understand. The ordinary telegraph is like a very long cat. You pull the tail in New York, and it meows in Los Angeles. The wireless is the same, only without the cat.