|Protagoras ( c. 490 – c. 420 BC) was a pre-Socratic Greek philosopher and is numbered as one of the sophists by Plato.|
Protagoras is credited with the philosophy of relativism. Protagoras meant that each individual is the measure of how things are perceived by that individual. According to the philosophy of Protagoras, there is no absolute evaluation of the nature of a temperature because the evaluation will be relative to who is perceiving it.
The famous sophist Protagoras took on a pupil, Euathlus, on the understanding that the student pay Protagoras for his instruction after he wins his first court case.
Protagoras argued that if he won the case he would be paid his money. If Euathlus won the case, Protagoras would still be paid according to the original contract, because Euathlus would have won his first case.
Euathlus, however, claimed that if he won, then by the court’s decision he would not have to pay Protagoras. If, on the other hand, Protagoras won, then Euathlus would still not have won a case and would therefore not be obliged to pay.