“Most of the philosophers adjudged great in the history of Western thought held that humans are fundamentally different from the other animals. Plato, Aristotle, Marcus Aurelius, Epictetus, Augustine, Aquinas, Descartes, Spinoza, Pascal, Locke, Leibniz, Rousseau, Kant, and Hegel were all proponents ‘of the view that man differs radically in kind from [all] other things’; except for Rousseau, they all held the essential human distinction to be our ‘reason, intellect, thought, or understanding.’ Almost all of them believed that our distinction arises from something made neither of matter nor of energy that resides within the bodies of humans, but of no one else on Earth. No scientific evidence for such a 'something’ has ever been produced. Only a few of the great Western philosophers—David Hume, for instance—argued, as Darwin did, that the difference between our species and others were only of degree.”
— Carl Sagan & Ann Druyan, ‘Shadows of Forgotten Ancestors’
