Platonism, Early and Middle
Authors: Dillon John 
Published: September 2018

Platonism is the body of doctrine developed in the school founded by Plato, both before and (especially) after his death in 347 bc. The first phase, usually known as ‘Early Platonism’ or the ‘Early Academy’, ran until the 260s bc, and is represented above all by the work of Plato’s first three successors, Speusippus, Xenocrates and Polemo. After an interval of nearly two centuries during which the Academy became anti-doctrinal in tendency, doctrinal Platonism re-emerged in the early first century bc with Antiochus, whose school the ‘Old Academy’ claimed to be a revival of authentic Platonism, although its self-presentation was largely in the terminology forged by the Stoics. The phase from Antiochus to Numenius is conventionally known as Middle Platonism, and prepared the ground for the emergence of Neoplatonism in the work of Plotinus. Its leading figures are Antiochus, Eudorus, Plutarch of Chaeronea, Atticus, Alcinous, Albinus, Calvenus Taurus and Numenius. Its influence is also visible in major contemporary thinkers like the Jewish exegete Philo of Alexandria and the doctor Galen.
Like Neoplatonism, Early and Middle Platonism were founded on a very close reading of the text of Plato, especially the Timaeus, often facilitated by commentaries, and further supplemented by knowledge of his ‘unwritten doctrines’. However, Early and Middle Platonists did not develop nearly so elaborate a metaphysics as the Neoplatonists, and there was a much greater concentration on ethics. Most Middle Platonists regarded Aristotle as an ally, and incorporated significant parts of his thought into Platonism, especially in ethics and logic. Some were Neo-Pythagorean in tendency, and most claimed in some sense to be able to trace Platonic thought back to Pythagoras.
The Platonists developed the dualism of the One (an active, defining principle) and the Indefinite Dyad (an indeterminate, material principle), bequeathed by Plato, especially through his oral teachings. These eventually emerged as, respectively, God and matter, supplemented by the Platonic Forms, which Middle Platonists typically identified with God’s thoughts. The world-soul was distinguished from the demiurge or creator, who was in turn either distinguished from or collapsed into the primary divinity, a supreme intellect. Some, notably Plutarch, postulated in addition a counterbalancing evil world-soul. As regards the human soul, Plato’s division of it into a rational plus two irrational parts was maintained, along with his doctrine of transmigration. There was also an increasing focus on the intermediary role played by daemons in the functioning of the world.
In ethics, most Middle Platonists came to effect an assimilation between Plato’s and Aristotle’s views. All agreed with Plato and Aristotle, against the Stoics, that as well as moral there are also non-moral goods, such as health and wealth. While there was a consensus that the latter are not necessary for happiness, some, notably Antiochus, defended the view that non-moral goods are indispensable, at least to supreme happiness. In addition, Aristotle’s doctrine that virtue lies in a ‘mean’ became a central feature of Platonist ethics. As for the ‘goal’ or ‘end’ (telos) of life, this came from the first century bc onwards, perhaps starting with Eudorus, to be specified by Platonists as ‘likeness to God’. Finally, the issue of determinism was, in the wake of Hellenistic philosophy, recognized as important by Middle Platonists, who defended the existence of free will.
Platonism never developed its own logic, but adopted Peripatetic logic, including both syllogistic and the theory of categories, both of which, it was claimed, had been anticipated by Plato.