4Rene Descartes. Animal is Machine. in Susan J Armstrong, Su an Armstrong, ed. Environmental Ethics : Divergence and Convergence [ M]. McGraw - Hill, 1993.
5Immanuel Kant. Rational Beings Alone Have Moral Worth, in Louis P. Pojman. Environmental Ethics:dings in The - ory and Applic- tion [ M ]. Wadsworth,2000.
