The year 155 B.C. was signalised by an important event, if not in the history of ideas, at least in the history of their diffusion. This was the despatch of an embassy from the Athenian people to the Roman Senate, consisting of three philosophers, the heads of their respective schools—Carneades the Academician, Critolaus the Peripatetic, and Diogenes the Stoic. Philosophic teaching, once proscribed at Athens, had, at the time of which we are speaking, become her chief distinction, and the most honourable profession pursued within her precincts. It was, then, as natural that an important mission should be confided to the most eminent representatives of the calling in question as that high ecclesiastics should be similarly employed by Rome in later ages, or that German university towns should send professors to represent their interests in the imperial Diet. But the same fate that befalls an established religion had befallen an established philosophy. An attempt to impose restrictions on the liberty of teaching had, indeed, been successfully resisted, and the experiment was never repeated.[212] Nevertheless, the teachers themselves lost as much in true dignity as they gained in affluence and popular estimation. In all probability, the threat of death would not have induced Socrates to undertake the task which was, apparently, accepted without compulsion and as an honourable duty by his successors. The Athenians had made an unprovoked raid on the town of Oropus; the affair had been referred to arbitration; and the aggressors had been sentenced to pay a fine of 500 talents. It was to obtain a remission of this sentence that the three Scholarchs were sent on an embassy to the Roman Senate.