The Roman philosopher and statesman Marcus Tullius Cicero (106–43 b.c.e.) is the chief source for Academic skepticism. His Academica (45 b.c.e.) reports on the teachings of Arcesilaus (315–240 b.c.e.) and Carneades (214–129 b.c.e.), both heads of the Academy, and he claims allegiance to the Academic school. St. Augustine of Hippo's earliest extant work, Contra Academicos (Against the Academics; 386 c.e.), is also an important source of knowledge about Academic skepticism.
Socrates can be placed at the origins of skepticism if it is understood that he only asked questions and did not teach positive doctrines. Plato and Aristotle strayed from his path when they claimed to know the truth. Arcesilaus gave renewed vigor to skepticism, arguing against the opinions of all men, as Cicero put it. But he also showed that skeptics could make choices in accordance with the eulogon (the reasonable) in the absence of truth. Carneades, also a master of arguing on both sides of every issue, refined this into the standard of the pithanon (the credible). Cicero translated this into Latin as probabile, setting the stage for the skeptics' claim to live by the probable in the absence of truth.
Manuscripts of Cicero's Academica were available in the Middle Ages to figures such as John of Salisbury (1115–1180), who used it to underpin defenses of liberty of thought and speech. The text was first printed at Rome in 1471, followed by numerous commentaries and annotations. By 1600 more than 100 editions had been published.