Patriotism requires less and less of making the eagle scream, but more and more of making him think.

Conservation is a state of harmony between men and land.

One swallow does not make a summer, but one skein of geese, cleaving the murk of March thaw, is the Spring.

If in a city we had six vacant lots available to the youngsters of a certain neighborhood for playing ball, it might be "development" to build houses on the first, and the second, and the third, and the fourth, and even the fifth, but when we build houses on the last one, we forget what houses are for.

No matter how intently one studies the hundred little dramas of the woods and meadows, one can never learn all the salient facts about any one of them.

All ethics so far evolved rest upon a single premise: that the individual is a member of a community of interdependent parts.

Our grandfathers were less well-housed, well-fed, well-clothed than we are. The strivings by which they bettered their lot are also those which deprived us of [Passenger] pigeons. Perhaps we now grieve because we are not sure, in our hearts, that we have gained by the exchange. The gadgets of industry bring us more comforts than the pigeons did, but do they add as much to the glory of the spring?