I believe, indeed, that overemphasis on the purely intellectual attitude, often directed solely to the practical and factual, in our education, has led directly to the impairment of ethical values. I am not thinking so much of the dangers with which technical progress has directly confronted mankind, as of the stifling of mutual human considerations by a 'matter-of-fact' habit of thought which has come to lie like a killing frost upon human relations. Without 'ethical culture' there is no salvation for humanity.
The scientist finds his reward in what Henri Poincare calls the joy of comprehension, and not in the possibility of application to which any discovery may lead.
All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.
What is the meaning of human life, or, for that matter, of the life of any creature? To know the answer to this question means to be religious. You ask: Does it make any sense, then, to pose this question? I answer: The man who regards his fellow creatures as meaningless is not merely unhappy but hardly fit for life.
I know what it's like to see one's mother go through the agony of death and be unable to help; there is no consolation. We all have to bear such heavy burdens, for they are unalterably linked to life.