The Protagorean Fallacy.
It was the Pre-Socratic Greek philosopher, Protagoras ( c. 490- c. 420 BCE), numbered among the 'Sophists' by Plato, who coined the phrase 'Man is the measure of all things', taken up enthusiastically by the Renaissance humanists. Plato believed him to be denying the existence of objective truth, and this is borne out when one examines the Protagoras quotation in full: 'Man is the measure of all things: of the things that are, that they are, of the things that are not, that they are not.' The Greek version of this reads: ' pant ōn chr ēmat ōn metron estin anthrōpos, tōn men ontōn hōs estin, tōn de ouk ontōn hōs ouk estin. ' A rather less sexist English translation would read: 'Humans are the measure of all things: of the things that exist, and of the things that don't.' This is the idea that reality is purely subjective, and that whatever appears to be the case for any given individual is true for that person. So, if the weather is cold fo...