Science has done more for the development of western civilization in one hundred years than Christianity did in eighteen hundred years.

The budget for nuclear forces in the United States is on the order of $25 billion or so. That includes warheads, delivery systems, command and control; does not include environmental clean-up, which is another maybe $10 billion or so. So that's about 5% of the U.S. military budget.

The Universe is a pretty big place... And the one thing I know about nature is it hates to waste anything. So I guess I'd say if it is just us, an awful lot of space is going to waste. The earth is not alone, it is not like a single apple on a tree; there are many apples on the tree, and there are many trees in the orchard.

Man takes root at his feet, and at best he is no more than a potted plant in his house or carriage till he has established communication with the soil by the loving and magnetic touch of his soles to it.

I seldom go into a natural history museum without feeling as if I were attending a funeral.

The smallest deed is better than the greatest intention.

Natural history is a matter of observation; it is a harvest which you gather when and where you find it growing. Birds and squirrels and flowers are not always in season, but philosophy we have always with us. It is a crop which we can grow and reap at all times and in all places and it has its own value and brings its own satisfaction.