Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction.

I am an optimist by nature. But I have to admit, it's getting kind of scary.

Humanity is part of nature, a species that evolved among other species. The more closely we identify ourselves with the rest of life, the more quickly we will be able to discover the sources of human sensibility and acquire the knowledge on which an enduring ethic, a sense of preferred direction, can be built.

Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction.

Give me, indulgent gods! with mind serene, And guiltless heart, to range the sylvan scene; No splendid poverty, no smiling care, No well-bred hate, or servile grandeur, there.

Their overall satisfaction with their lives appears to be greater if they're more physically active.