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man is the measure of all things

phr. (an expression of) the doctrine that all knowledge is subjective, being derived from observations made by humans, and there can be no objective truth

Usage examples of "man is the measure of all things".

I say pretend because it is my view that despite the basic conservatism of the Athenian people when it comes to maintaining the forms of old things, the essential spirit of these people is atheistic -- or as a Greek cousin of mine pointed out not long ago, with dangerous pride, man is the measure of all things.

And what you learn from elections is that man is the measure of all things.