Carneades (kɑrˈniːədiːz; Καρνεάδης, Karneadēs, "of Carnea"; 214/3–129/8 BC) was a Greek philosopher and perhaps the most prominent head of the Skeptical Academy in ancient Greece. He was born in Cyrene. By the year 159 BC, he had begun to attack many previous dogmatic doctrines, especially Stoicism and even the Epicureans whom previous skeptics had spared. As scholarch (leader) of the Academy, he was one of three philosophers sent to Rome in 155 BC where his lectures on the uncertainty of justice caused consternation among leading politicians. He left no writings. Many of his opinions are known only via his successor Clitomachus. He seems to have doubted the ability not just of the senses but of reason too in acquiring truth. His skepticism was, however, moderated by the belief that we can, nevertheless, ascertain probabilities (not in the sense of statistical probability, but in the sense of persuasiveness) of truth, to enable us to act.
Carneades, the son of Epicomus or Philokomus, was born at Cyrene, North Africa in 214/213 BC. He migrated early to Athens. There he attended the lectures of the Stoics, learning their logic from Diogenes of Babylon and studying the works of Chrysippus. He subsequently focused his efforts on refuting the Stoics, attaching himself to the Platonic Academy, which had suffered from the attacks of the Stoics. On the death of Hegesinus of Pergamon, he was chosen scholarch (head) of the Academy. His great eloquence and skill in argument revived the glories of the Academic Skeptics. He asserted nothing (not even that nothing can be asserted), and carried on a vigorous argument against every dogma maintained by other sects.
In the year 155 BC, when he was fifty-eight years old, he was chosen with the Stoic Diogenes of Babylon and the Peripatetic Critolaus to go as ambassadors to Rome to deprecate the fine of 500 talents which had been imposed on the Athenians for the destruction of Oropus. During his stay at Rome, he attracted great notice from his eloquent speeches on philosophical subjects.