Graduation Year


Document Type




Degree Granting Department


Major Professor

Martin Schönfeld

Co-Major Professor

Roger Ariew

Committee Member

Stephen Turner


environmental ethics, nonhuman animals, Montaigne, skepticism, active force, categories


René Descartes’ 1637 “bête machine” characterization of nonhuman animals has assisted in the strengthening of the Genesis 1:26 and 1: 28 disparate categorization of nonhuman animals and human animals. That characterization appeared in Descartes’ first important published writing, the Discourse on the Method, and can be summarized as including the ideas that nonhuman animals are like machines; do not have thoughts, reason or souls like human animals; and thus, cannot be categorized with humans; and, as a result, do not experience pain or certain other feelings. This characterization has impeded the primary objective of environmental ethics - the extension of ethical consideration beyond human animals - and has supported the argument that not only the nonhuman animal but also the rest of nature has only instrumental worth/value. As is universally recognized, Gottfried Wilhelm Leibniz, just a few decades after Descartes’ death, took issue with Descartes’ dualism by arguing that the Leibnizian monad, with its active power, was the foundation of, at least, all of life. This argument must result in the conclusion that nonhuman and human animals are necessarily categorized collectively, just as Charles Darwin later argued. In fact, when the writings of Descartes and Michel de Montaigne are reviewed, it becomes apparent that Descartes never believed his bête machine characterization but embraced it to achieve not only his philosophical objectives but also his anatomical and physiological objectives. Philosophically, Descartes was answering Montaigne’s skepticism and his use of nonhuman animal examples to discredit human reason. Also, Descartes spent a major part of, at least, the last twenty-two years of his fifty-four year life dissecting nonhuman animals. Finally, the role that the politics and policies of the Christian institutions played in these matters is of primary importance. Similar politics and policies of the Christian institutions have since played, and still play, an important role in the continuing, unreasonable, disparate categorization of human animals and nonhuman animals. Philosophy seems to be the only discipline that can, if it will, take issue with that characterization.