Skepticism was a philosophical movement in ancient Greece. The Skeptics tried to weaken people’s confidence in observation and reason as trustworthy guides to understanding the world, and they argued against all dogmatic schools of philosophy. They believed that people can be certain of the nature of their observations but cannot be sure that their observations reflect the real world. According to the Skeptics, people must suspend judgment regarding the truth or falsity of their perceptions.
There were two main schools of Skepticism in ancient Greece. The first school regarded Pyrrho of Elis, who lived from about 361 to 270 B.C., as its founder, and was called Pyrrhonian Skepticism. It was developed by Anesidemus and is presented most fully in the writings of Sextus Empiricus, who lived about A.D. 200. The goal of this school was a tranquillity of life that follows from suspending judgment.
The second school of Skepticism was developed in the school of philosophy founded by Plato and was known as academic Skepticism. This school was begun by Arcesilaus in the 200’s B.C., and it was continued by Carneades in the 100’s B.C. These Skeptics were concerned with revealing the difficulties of other philosophers’ points of view. Summaries of these Skeptic doctrines are preserved in Cicero’s Academica.
