 There is a long and distinguished line of philosophers, including David Hume, Immanuel Kant, Gottlob Frege, and Bertrand Russell, who followed Aristotle in denying that existence is a separate property of individuals, even as they rejected other aspects of Aristotle’s views. Hume argued (in A Treatise of Human Nature 1.2.6) that there is no impression of existence distinct from the impression of an object, which is ultimately on Hume’s view a bundle of qualities. As all of our contentful ideas derive from impressions, Hume concluded that existence is not a separate property of an object. Kant’s criticism of the ontological arguments for the existence of God rested on a rejection of the claim that existence is a property of an object. Proponents of the ontological argument argue that the concept of God as an entity with all perfections or a being of which no greater can be conceived entails God’s existence, as existence is a perfection and a being that exists is greater than a being that does not exist. Kant objected (in his Critique of Pure Reason, A596/B624-A602/B630) that existence is not a property. “Thus when I think a thing, through whichever and however many predicates I like (even in its thoroughgoing determination), not the least bit gets added to the thing when I posit in addition that this thing is. For otherwise what would exist would not be the same as what I had thought in my concept, but more than that, and I could not say that the very object of my concept exists” (A600/B628). Finally, both Frege and Russell maintained that existence is not a property of individuals but instead a second-order property—a property of concepts, for Frege, and of propositional functions, for Russell. Crudely, to say that dinosaurs do not exist is to say that the property of being a dinosaur is not instantiated; to say that Jean-Baptiste Botul does not exist is to say that some property—say, the property of being a unique post-war critic of Kant and father of Butolism—is not instantiated. In neither case is it to say of some individual that it does not exist, which neither Frege nor Russell thought made sense.