“The value the world sets upon motives is often grossly unjust and inaccurate. Consider, for example, two of them: mere insatiable curiosity and the desire to do good. The latter is put high above the former, and yet it is the former that moves one of the most useful men the human race has yet produced: the scientific investigator. What actually urges him on is not some brummagem idea of Service, but a boundless, almost pathological thirst to penetrate the unknown, to uncover the secret, to find out what has not been found out before. His prototype is not the liberator releasing slaves, the good Samaritan lifting up the fallen, but a dog sniffing tremendously at an infinite series of rat-holes.”

“After some hours, the dogs, exhausted by running round, almost dead, their tongues hanging out, set upon one another and, not knowing what they are doing, tear one another into thousands of pieces with incredible rapidity. Yet they do not do this out of cruelty. One day, a glazed look in her eyes, my mother said to me: ‘When you are in bed and you hear the barking of the dogs in the countryside, hide beneath your blanket, but do not deride what they do: they have an insatiable thirst for the infinite, as you, and I, and all other pale, long-faced human beings do.’ Since that time, I have respected the dead woman’s wish. Like those dogs I feel the need for the infinite. I cannot, cannot satisfy this need. I am the son of a man and a woman, from what I have been told. This astonishes me…I believed I was something more.”

“To produce a valuable observation, one has first to have an idea of what to observe, a preconception of what is possible. Scientific advances often come from uncovering a hitherto unseen aspect of things as a result, not so much of using new instruments, but rather of looking at objects from a different angle. This look is necessarily guided by a certain idea of what this so-called reality might be. It always involves a certain conception about the unknown, that is, about what lies beyond that which one has logical or experimental reasons to believe.”

“To say to the slave who has not been emancipated 'Do not behave as a slave' is to mock his enslavement. But to say the same to the slave who has been set free is the necessary appeal to put into effect the privileges and rights of his liberation.”

“Political tags — such as royalist, communist, democrat, populist, fascist, liberal, conservative, and so forth — are never basic criteria. The human race divides politically into those who want people to be controlled and those who have no such desire. The former are idealists acting from highest motives for the greatest good of the greatest number. The latter are surly curmudgeons, suspicious and lacking in altruism. But they are more comfortable neighbors than the other sort.”

“Men of genius are made not by new ideas, but by an idea which possesses them, namely, that what has been said has not yet been sufficiently said.”