Aenesidemus (
Greek: Αἰνησίδημος
Ainēsidēmos) was a
Greek sceptical philosopher, born in
Knossos on the island of
Crete. He lived in the 1st century BC, taught in
Alexandria and flourished shortly after the life of
Cicero. He was probably a member of
Plato's Academy, but due to his rejection of their theories he revived the principle of
epoché (εποχή), or suspended judgement, originally proposed by
Pyrrho and
Timon, as a solution to what he considered to be the insoluble problems of
epistemology. His school is most commonly referred to as
Pyrrhonism, but also as the third
sceptic school. His chief work, the
Pyrrhoneia (Πυρρώνειοι λóγοι) discussed four main ideas: the reasons for scepticism and doubt, arguments against causality and truth, a physical theory and an ethical theory. Of these, the former are the most significant and his reasons for the suspension of judgment were organized into ten "tropes", or modes. Very little is known about him as none of his works have survived, though he has been mentioned and discussed in detail by
Photius (in his
Myriobiblion) and
Sextus Empiricus, and also to a lesser extent by
Diogenes Laertius and
Philo of Alexandria.
