Fifth-century Greek tragedy and visual art centres on interaction between people, including antithetical relations, reflecting a society shaped by monetised exchange and commerce. Platonic metaphysics is focused on unchanging being, placing supreme value on the possession of money and devaluing or excluding exchange and interaction. Although dialogues such as the Phaedo contain the idea of the unity of opposites, and binary opposites such as body and soul, Platonic metaphysics aims at the negation of opposites, and thus of antithesis. The contrast between being and seeming emerges in fifth-century tragedy and philosophy, but it is given much greater prominence by Plato and is linked with the theory of Forms. One of the Platonic accounts of the relationship between Forms and particulars is in terms of original (Form) and copy or image (particulars). Plato is the first to offer a theorization of the idea of the image (in the Sophist) and to define the idea of mere image (not reality). Plato’s treatment of the being-seeming relation, like the theory of Forms generally, expresses the reification of the value of money, treated as the basis of possession, excluding exchange.