Carneades (/kɑːrˈniːədiːz/; Greek: Καρνεάδης, Karneadēs, "of Carnea"; 214/3–129/8 BC) was a Greek philosopher, 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. His ideas were passed on to us through his successor Clitomachus whose own books were lost but relayed to us indirectly in the writings of Cicero and Sextus Empiricus. 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.