Xenocrates of Chalcedon was an ancient Greek philosopher, mathematician, and a prominent disciple of Plato. After Plato's death, he succeeded Speusippus as the head of the Platonic Academy from 339 to 314 BC. His philosophical teachings emphasized the tripartite division of philosophy into logic, physics, and ethics, a structure he is credited with first proposing. Though none of his extensive writings have survived, his ideas influenced later Platonists and Stoics, particularly his doctrines on divinity and the nature of the soul.