"The feeling of awed wonder that science can give us is one of the highest experiences of which the human psyche is capable. It is a deep aesthetic passion to rank with the finest that music and poetry can deliver. It is truly one of the things that makes life worth living and it does so, if anything, more effectively if it convinces us that the time we have for living it is finite."
"... people usually experience as work what they have to do by some external force, whereas to experience something as play, they must feel that they have chosen to do it voluntarily."