Bion of Borysthenes (Greek: Βίων Βορυσθενίτης, gen.: Βίωνος; c. 325 – c. 250 BC) was a Greek philosopher. After being sold into slavery, and then released, he moved to Athens, where he studied in almost every school of philosophy. It is, however, for his Cynic-style diatribes that he is chiefly remembered. He satirized the foolishness of people, attacked religion, and eulogized philosophy.