Nature is all the animals, plants, and other things in the world that are not made by people, and all the events and processes that are not caused by people.

The tree which moves some to tears of joy is in the eyes of others only a green thing which stands in the way. Some see nature all ridicule and deformity, and by these I shall not regulate my propositions. And some see no nature at all. But to the eyes of the man of imagination, nature is imagination itself." –William Blake