The surface of the earth is not simply a stage on which the thousands of present and past inhabitants played their parts in turn. There are much more intimate relations between the earth and the living organisms which populated it, and it may even be demonstrated that the earth was developed because of them.

A smattering of everything is worth little. It is a fallacy to suppose that an encyclopaedic knowledge is desirable. The mind is made strong, not through much learning, but by the thorough possession of something.

Facts are stupid until brought into connection with some general law.

The surface of the earth is not simply a stage on which the thousands of present and past inhabitants played their parts in turn. There are much more intimate relations between the earth and the living organisms which populated it, and it may even be demonstrated that the earth was developed because of them.

I now never make the preparations for penetrating into some small province of nature hitherto undiscovered without breathing a prayer to the Being who hides His secrets from me only to allure me graciously on to the unfolding of them.

The time has come when scientific truth must cease to be the property of the few, when it must be woven into the common life of the world.

Philosophers and theologians have yet to learn that a physical fact is as sacred as a moral principle. Our own nature demands from us this double allegiance.