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.

One can only learn his powers of action by action, and his powers of thought by thinking

Communing with God is communing with our own hearts, our own best selves, not with something foreign and accidental. Saints and devotees have gone into the wilderness to find God; of course they took God with them, and the silence and detachment enabled them to hear the still, small voice of their own souls, as one hears the ticking of his own watch in the stillness of the night.

The thing that I focus on because I don't think it gets enough attention is that among the world's major powers, there is still a nuclear balance of terror - I'm talking about between the United States and Russia, the United States and China.

The rocks have a history; gray and weatherworn, they are veterans of many battles; they have most of them marched in the ranks of vast stone brigades during the ice age; they have been torn from the hills, recruited from the mountaintops, and marshaled on the plains and in the valleys; and now the elemental war is over, there they lie waging a gentle but incessant warfare with time and slowly, oh, so slowly, yielding to its attacks!

Science is a capital or fund perpetually reinvested; it accumulates, rolls up, is carried forward by every new man. Every man of science has all the science before him to go upon, to set himself up in business with. What an enormous sum Darwin availed himself of and reinvested! Not so in literature; to every poet, to every artist, it is still the first day of creation, so far as the essentials of his task are concerned. Literature is not so much a fund to be reinvested as it is a crop to be ever new-grown.

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.