One of the things that has helped me as much as any other is not how long I am going to live, but how much I can do while living.

I love to think of nature as an unlimited broadcasting station, through which God speaks to us every hour, if we will only tune in.

Start where you are, with what you have. Make something of it and never be satisfied.

When I touch that flower, I am not merely touching that flower. I am touching infinity. That little flower existed long before there were human beings on this earth. It will continue to exist for thousands, yes, millions of years to come.

God gave them [the discoveries] to me; how can I sell them to someone else?

When our thoughts - which bring actions - are filled with hate against anyone, Negro or white, we are in a living hell. That is as real as hell will ever be.

The centre of his world was the south where he was born in slavery some 79 years ago and where he did his work as a creative scientist.