Famous quotes containing the words species and/or exchanged:
“Let us guard against saying that death is opposed to life. The living is merely a species of the dead, and a very rare species.”
—Friedrich Nietzsche (1844–1900)
“If it is asserted that civilization is a real advance in the condition of man,—and I think that it is, though only the wise improve their advantages,—it must be shown that it has produced better dwellings without making them more costly; and the cost of a thing is the amount of what I will call life which is required to be exchanged for it, immediately or in the long run.”
—Henry David Thoreau (1817–1862)