As to gods, I have no way of knowing either that they exist or do not exist, or what they are like.
Man is the measure of all things.
There are two sides to every question.
Protagoras was a greek sophist, who took an idea like this
It is a spring day in Athens.
A visitor from Sweden days the weather is warm, while a visitor from Egypt says the weather is cold. BOTH people are speaking the truth.
Truth is dependent upon perspective and is therefore relative.
ERGO... man is the measure of all things.
Protagoras, who became an influential Sophist, lectured in law and rhetoric to anyone that would pay him, he mostly talked about practical matters that would help win a civil case rather than trying to prove a point but as he taught he began to see philosophical applications to what he was saying.
to him, since he helped to fight civil cases, every thought, every argument had two sides to it. His point was not to prove a point worthwhile, but to merely make the argument for it better. it is man opinion that makes a point valuable or not.
He took a legal method and applied it to philosophy. This was a new thing to do. It placed man as the center of philosophical thinking rather than God. God was taken out of the realm of philosophy. To Protagoras, wondering about the cosmos or the beginning of things was a pointless endeavor as we simply could never know the answers. He was very focused on the practical.
To Protagoras, "something is ethical or right, only because a person or society judges it to be so".
Wow....
Protagoras would fit into modern society really well don't you think? With today's emphasis on "well if he thinks it's okay, then it's okay" thinking that is going on. i find it sad. Life would always be in flux wouldn't it? With popular opinion being the guide to right and wrong and not even considering God at all.
Sources:
The Philosophy Book
Quotes of Protagoras
internet encyclopedia of philosophy