In the span of my own lifetime I observed such wondrous progress in plant evolution that I look forward optimistically to a healthy, happy world as soon as its children are taught the principles of simple and rational living.

Religion grows with the intelligence of man, but all religions of the past and probably all of the future will sooner or later become petrified forms instead of living helps to mankind. Until that time comes, however, if religion of any name or nature makes man more happy, comfortable, and able to live peaceably with his brothers, it is good.

All my work has come about through a change in my earlier opinion of religion.

Of course it must, and our scientific men must be criticized boldly. They will not feel comfortable when you and I are through with them.

Obsolete misleading theologies bear the same relation to the essence of true religion that scarlet fever, mumps, and measles do to education.

Prayer may be elevating if combined with work, and they who labor with head, hands or feet have faith and are generally quite sure of an immediate and favorable reply.

Thinking is the greatest torture in the world for most people.