For more than two thousand years, philosophers have postulated the existence of objects that exist outside space and time. Plato argued that as well as the particular objects given to us in sense experience, such as human beings, cats, beds, and cartwheels, there exists a quite different type of entity, which he called Forms or Ideas. Examples of Plato's Forms are Beauty, Circularity, Whiteness, Humanity, and Cathood. These Forms are what are supposedly designated by predicates in subject-predicate sentences. The Form of Whiteness is designated by the predicate in "My cat is white". Forms are what account for the sameness-of-property of particulars. It is in virtue of their participation in the Form of Humanity that Socrates, Confucius, Gerónimo, and Sylvester Stallone are all human. According to Plato, the Forms are eternal, unchanging, and have no location in space or time.¹