Protagoras
From Philosopedia
Protagoras of Abdera (c. 481- c. 420 B.C.E.)
The most celebrated of the early Sophists, Protagoras - like Democritus - was from Abdera on the north coast of the Aegean. In his travels throughout Greece he met Pericles and was invited to help write the constitution for Thurii, an Athenian colony.
By some he was termed impious, but Plato in Meno 91e claims that Protagoras had a good reputation. Those who found him impious disapproved of his doubts about the existence and nature of the gods.
C. C. W. Taylor of Corpus Christi College, Oxford, has written of Protagoras's fame in having written,
- Man is the measure of all things:of things that are, that they are, and of things which are not, that they are not.
- i.e., the thesis that all sensory appearances and all beliefs are true for the person whose appearance or belief they are: on the most plausible construal that doctrine attempts to eliminate objective and truth altogether.
Democritus and Plato (in the Theaetetus) attacked his outlook on the ground that
- it is self-refuging; if all beliefs are true, then the belief that it is not the case that all beliefs are true is itself true.
Such a refutation fails, according to Taylor,
- because it ignores the relativization of truth in the theory, it may be reinstated as follows: either the theory undermines itself by asserting as an objective truth that there is no objective truth or it merely asserts as a subjective truth that there is no objective truth. But to assert a subjective truth is to make no assertion. So either the theory refutes itself, or it asserts nothing.
Plato, in the Protagoras,
- represents him as maintaining a fairly conservative form of social morality, based on a version of social contract theory; humans need to develop social institutions to survive in a hostile world, and the basic social virtues, justice and self-control, must be generally observed if those institutions are to flourish.
Protagoras taught mainly in athens, where he presented a system of practical wisdom fitted to train people for citizens' duties. All his works have been lost, except a fragment of his treatise On the Gods.
