A system of skeptic philosophy taught by Pyrrho of Elis founder of Pyrrhonian school, holding that nothing can be certainly known and that suspension of judgement is true wisdom and the source of happiness. Its central doctrine concerns the impossibility of attaining certainty of knowledge.

Greek philosopher, born in Elis, the founder of a school of Greek skepticism known as Pyrrhonism. Lived from around 365 BC to 275 BC.

His teacher was the Greek philosopher Anaxarchus, a disciple of the Greek philosopher Democritus.

Pyrrho accompanied Alexander III, King of Macedonia, on his expedition to the East, and became acquainted with the teachings of the Persian magi and the Indian Brahmans.

Much of Pyrrho's long life was spent in seclusion. He did not put his doctrines into writing, and they are known chiefly from the works of his follower Timon of Phlius, a philosopher and writer of satires.

Pyrrho taught that the real nature of things can never be truly comprehended and hence objective knowledge is impossible to attain.

He held that the correct attitude for the philosopher is imperturbability and complete suspension of judgment, and that in this attitude lies freedom from passion, calmness of mind, and tranquility of soul, which comprises man's greatest qualities. Pyrrho was the first to introduce the idea of pure skepticism into Greek philosophy, and he is therefore regarded by many as the father of skepticism.

The principles of skepticism were first given systematic formulation by the Pyrrhonists, a school of Greek philosophy deriving its name from its founder, Pyrrho of Elis.

Pyrrho maintained that man can know nothing of the nature of things, and that consequently it is the part of wisdom to suspend judgment.

Timon of Philius, Pyrrho's pupil, carried skepticism to its logical conclusion by asserting that equally good reasons can be adduced both for and against a philosophical proposition.

With respect to skepticism itself, this assertion implies that equally valid reasons can be given for an antiskeptical as for a skeptical view point.

The members of the so-called Middle Academy, which was intermediate between the Old Academy of Plato and the New Academy of Carneades and Clitomachus, were somewhat less radical in their skepticism than the Pyrrhonists, since they entertained some doubt as to the value of a skepticism that doubted everything.

Carneades maintained that no beliefs can be proved conclusively but that some can be shown to be more probable than others.

Aenesidemus set forth in his Ten Tropes ten arguments in support of the skeptical position. Another noted skeptic of antiquity was the Greek physician Sextus Empiricus, whose writings are an important source of information about other schools of philosophy as well as skepticism.

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