Protagoras of Abdera was one of several fifth century Greek
thinkers (including also Gorgias, Hippias, and Prodicus)
collectively known as the Older Sophists, a group of traveling
teachers or intellectuals who were experts in rhetoric (the
science of oratory) and related subjects. Protagoras is known
primarily for three claims (1) that man is the measure of all
things (which is often interpreted as a sort of radical
relativism) (2) that he could make the “worse (or weaker)
argument appear the better (or stronger)” and (3) that one could
not tell if the gods existed or not. While some ancient sources
claim that these positions led to his having been tried for
impiety in Athens and his books burned, these stories may well
have been later legends. Protagoras’ notion that judgments and
knowledge are in some way relative to the person judging or
knowing has been very influential, and is still widely discussed
in contemporary philosophy. Protagoras’ influence on the history
of philosophy has been significant. Histo