"Be unselfish. That is the first and final commandment for those who would be useful and happy in their usefulness. If you think of yourself only, you cannot develop because you are choking the source of development, which is spiritual expansion through thought for others"
"I was married to Margaret Joan Howe in 1940. Although not a scientist herself she has contributed more to my work than anyone else by providing a peaceful and happy home"
"Try to be happy in this present moment, and put not off being so to a time to come, as though that time should be of another make from this which has already come and is ours"