Famous quotes containing the words species and/or exchanged:
“A man, to be greatly good, must imagine intensely and comprehensively; he must put himself in the place of another and of many others; the pains and pleasures of his species must become his own.”
—Percy Bysshe Shelley (17921822)
“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 (18171862)