Hunger, love, pain, fear are some of those inner forces which rule the individual's instinct for self preservation.

So I am living without fats, without meat, without fish, but am feeling quite well this way. It always seems to me that man was not born to be a carnivore.

A man's ethical behaviour should be based effectually on sympathy, education, and social ties and needs; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.

I believe in intuition and inspiration...at times I feel certain I am right while not knowing the reason.

Every serious scientific worker is painfully conscious of this involuntary relegation to an ever-narrowing sphere of knowledge, which threatens to deprive the investigator of his broad horizon and degrades him to the level of a mechanic.

In the middle of adversity there is great opportunity.

To my mind, to kill in war is not a whit better than to commit ordinary murder.