Bias (Greek: Βίας ο Πριηνεὺς, 6th century BCE), the son of Teutamus and a citizen of Priene was a Greek philosopher. Satyrus puts him as the wisest of all the Seven Sages of Greece. He was renowned for his goodness.

One of the examples of his great goodness is the legend that says that he paid a ransom for some women who had been taken prisoner. After educating them as his own daughters, he sent them back to Messina, their homeland, and to their fathers.

Also it is said that when some fishermen found The Brazen Tripod on which was inscripted: "For the Wisest", the fathers of the damsels came into an assembly. They concluded that Bias was the wisest among all men, so the tripod was presented to him as a token of gratitude for all that he had done for the city. Bias refused the honor with the words: "Apollo is the wisest". Another author notes that he consecrated the tripod at Thebes to Hercules.

Among the quotes attributed to Bias are:

• "The naïve men are easily fooled."
• "Most people are evil."
• "All men are wicked."
• "It is difficult to bear a change of fortune for the worse with magnanimity."
• "Choose the course which you adopt with deliberation; but when you have adopted it, then persevere in it with firmness."
• "Do not speak fast, for that shows folly."
• "Love prudence."
• "Speak of the Gods as they are."
• "Do not praise an undeserving man because of his riches."
• "Accept of things, having procured them by persuasion, not by force."
• "Cherish wisdom as a means of traveling from youth to old age, for it is more lasting than any other possession."

It is said that he was very energetic and eloquent when pleading causes; but that he always reserved his talents for the right side. In reference to which Demodicus of Alerius uttered the following enigmatical saying — "If you are a judge, give a Prienian decision." And Hipponax says, "More excellent in his decisions than Bias of Priene." (Diogenes Laertius, Book I, Chapter: The Life of Bias)

He also wrote about 2,000 verses on Ionia, to show in what matter a man might achieve happiness.

The legend says that he died as an old man, pleading a cause for his client. After he had finished speaking, he leaned back with his head on the bosom of his daughter's son. When the advocate on the opposite side had spoken, the judges decided in favor of Bias's client. At the end of the trial he was found dead on his grandson's bosom. The city buried him in the greatest magnificence.

In April, 1819, Schopenhauer wrote in his Reisebuch [Travel Diary]: "In the Vatican [Hall of Philosophers] there is the bust of Bias with the inscription of πλεἳστοι άνθρωπι κακοι [most men are bad]. Indeed this must have been his maxim."