"Man is a tool-using animal. Without tools he is nothing, with tools he is all."

"I have learned that success is to be measured not so much by the position that one has reached in life as by the obstacles which he has overcome while trying to succeed."

"I have always considered myself as an Agnostic..."

"Don't keep forever on the public road, going only where others have gone. Leave the beaten track occasionally and dive into the woods. Every time you do so you will be certain to find something that y…"

"I am a man of science, and I believe in the power of observation and experimentation."