“The complete irresponsibility of man for his actions and his nature is the bitterest drop which he who understands must swallow.”

“A man is at his youngest when he thinks he is a man, not yet realizing that his actions must show it.”

“He who would do battle with the many-headed hydra of human nature must pay a world of pain & his family must pay it along with him! & only as you gasp your dying breath shall you understand, your life amounted to no more than one drop in a limitless ocean!' Yet what is any ocean but a multitude of drops?”

“In order to live, man must act; in order to act, he must make choices; in order to make choices, he must define a code of values; in order to define a code of values, he must know what he is and where he is – i.e. he must know his own nature (including his means of knowledge) and the nature of the universe in which he acts – i.e. he needs metaphysics, epistemology, ethics, which means: philosophy. He cannot escape from this need; his only alternative is whether the philosophy guiding him is to be chosen by his mind or by chance.”

“Naturally, for a person who finds his identity in something other than his full organism is less than half a man. He is cut off from complete participation in nature. Instead of being a body, he 'has' a body. Instead of living and loving he 'has' instincts for survival and copulation.”

“Man's mind is his basic tool of survival. Life is given to him, survival is not. His body is given to him, its sustenance is not. His mind is given to him, its content is not. To remain alive, he must act, and before he can act he must know the nature and purpose of his action. He cannot obtain his food without a knowledge of food and of the way to obtain it. He cannot dig a ditch-or build a cyclotron-without a knowledge of his aim and of the means to achieve it. To remain alive, he must think”