"The good life is one inspired by love and guided by knowledge."

"Nothing can penetrate the loneliness of the human heart except the highest intensity of the sort of love the religious teachers have preached."

"I am not interested in the universe as a whole, but in certain parts of it."

"I am not interested in the universe as a mere collection of facts, but as a system of relations."

"Free thought has always been a perquisite of aristocracy."