We shall continue to have a worsening ecologic crisis until we reject the Christian axiom that nature has no reason for existence save to serve man. – Lynn White, Jr., "The Historical Roots of Our Ecologic Crisis," 1967

There is nothing in which the birds differ more from man than the way in which they can build and yet leave a landscape as it was before. – Robert Lynd, The Blue Lion and Other Essays

Man has lost the capacity to foresee and to forestall. He will end by destroying the earth. – Albert Schweitzer, quoted in James Brabazon, Albert Schweitzer

If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos. – Edward O. Wilson