Boundaries which mark off one field of science from another are purely artificial, are set up only for temporary convenience. Let chemists and physicists dig deep enough, and they reach common ground.

A calculating engine is one of the most intricate forms of mechanism, a telegraph key one of the simplest. But compare their value.

Is any knowledge worthless? Try to think of an example.

A superstition is a premature explanation that overstays its time.

Evolution pays and that is why there is evolution

Truth is better disengaged from error than torn from it.

We despair of changing the habits of men, still we would alter institutions, the habits of millions of men.