Scholarch in the context of Ancient Greece

Academic skepticism was the philosophy of the skeptical period of the Academy dating from around 266 BCE, when Arcesilaus became scholarch, until around 90 BCE, when Antiochus of Ascalon rejected skepticism, although individual philosophers, such as Favorinus and his teacher Plutarch, continued to defend skepticism after this date. Unlike the existing school of skepticism, the Pyrrhonists, they maintained that knowledge of things is impossible. Ideas or notions are never true; nevertheless, there are degrees of plausibility, and hence degrees of belief, which allow one to act. The school was characterized by its attacks on the Stoics, particularly their dogma that convincing impressions led to true knowledge. The most important Academics were Arcesilaus, Carneades, and Philo of Larissa. The most extensive ancient source of information about Academic skepticism is Academica, written by the Academic skeptic philosopher Cicero.

Panaetius (/pəˈniːʃiəs/; Ancient Greek: Παναίτιος, romanized: Panaítios; c. 185 – c. 110/109 BC) of Rhodes was an ancient Greek Stoic philosopher. He was a pupil of Diogenes of Babylon and Antipater of Tarsus in Athens, before moving to Rome where he did much to introduce Stoic doctrines to the city, thanks to the patronage of Scipio Aemilianus. After the death of Scipio in 129 BC, he returned to the Stoic school in Athens, and was its last undisputed scholarch. With Panaetius, Stoicism became much more eclectic. His most famous work was his On Duties, the principal source used by Cicero in his own work of the same name.

Arcesilaus (/ˌɑːrsɛsɪˈleɪ.əs/; Ancient Greek: Ἀρκεσίλαος; 316/5–241/0 BC) was a Greek Hellenistic philosopher. He was the founder of Academic Skepticism and what is variously called the Second or Middle or New Academy – the phase of the Platonic Academy in which it embraced philosophical skepticism.

Arcesilaus succeeded Crates of Athens as the sixth scholarch of the academy around 264 BC. He did not preserve his thoughts in writing, so his opinions can only be gleaned second-hand from what is preserved by later writers.

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.

Strato of Lampsacus (/ˈstreɪtoʊ/; Ancient Greek: Στράτων ὁ Λαμψακηνός, romanized: Strátōn ho Lampsakēnós, c. 335 – c. 269 BCE) was a Peripatetic philosopher, and the third director (scholarch) of the Lyceum after the death of Theophrastus. He devoted himself especially to the study of natural science, and increased the naturalistic elements in Aristotle's thought to such an extent, that he denied the need for an active god to construct the universe, preferring to place the government of the universe in the unconscious force of nature alone.

Diogenes of Babylon (also known as Diogenes of Seleucia; Ancient Greek: Διογένης Βαβυλώνιος; Latin: Diogenes Babylonius; c. 230 – c. 150/140 BC) was a Stoic philosopher. He was the head of the Stoic school in Athens, and he was one of three philosophers sent to Rome in 155 BC. He wrote many works, but none of his writings survived, except as quotations by later writers.

Crates of Athens (Greek: Κράτης ὁ Ἀθηναῖος; died 268–264 BC) was a Platonist philosopher and the last scholarch of the Old Academy.