Two years afterward he was sent as an envoy into the Peloponnesus, with the object of forming a union of the Greeks against Philip for the defense of their liberties.  But his mission was unsuccessful.  Toward the end of the same year he served as one of the ten ambassadors sent to Philip to discuss terms of peace.  The harangues of the Athenians at this meeting were followed in turn by a speech of Philip, whose openness of manner, pertinent arguments, and pretended desire for a settlement led to a second embassy, empowered to receive from him the oath of allegiance and peace.  It was during this second embassy that Demothenes says he discovered the philippizing spirit and foul play of Aeschines.  Upon their return to Athens, Aeschines rose before the assembly to assure the people that Philip had come to Thermopylae as the friend and ally of Athens.  “We, your envoys, have satisfied him,” said Aeschines.  “You will hear of benefits still more direct which we have determined Philip to confer upon you, but which it would not be prudent as yet to specify.”

But the alarm of the Athenians at the presence of Philip within the gates was not allayed.  The king, however, anxious to temporize with them until he could receive his army supplies by sea, suborned Aeschines, who assured his countrymen of Philip’s peaceful intentions.  On another occasion, by an inflammatory speech at Delphi, he so played upon the susceptibilities of the rude Amphictyones that they rushed forth, uprooted their neighbors’ harvest fields, and began a devastating war of Greek against Greek.  Internal dissensions promised the shrewd Macedonian the conquest he sought.  At length, in August, 338, came Philip’s victory at Chaeronea, and the complete prostration of Greek power.  Aeschines, who had hitherto disclaimed all connection with Philip, now boasted of his intimacy with the king.  As Philip’s friend, while yet an Athenian, he offered himself as ambassador to entreat leniency from the victor toward the unhappy citizens.

The memorable defense of Demosthenes against the attack of Aeschines was delivered in 330 B.C.  Seven years before this, Ctesiphon had proposed to the Senate that the patriotic devotion and labors of Demosthenes should be acknowledged by the gift of a golden crown—­a recognition willingly accorded.  But as this decision, to be legal, must be confirmed by the Assembly, Aeschines gave notice that he would proceed against Ctesiphon for proposing an unconstitutional measure.  He managed to postpone action on the notice for six years.  At last he seized a moment when the victories of Philip’s son and successor, Alexander, were swaying popular feeling, to deliver a bitter harangue against the whole life and policy of his political opponent.  Demosthenes answered in that magnificent oration called by the Latin writers ‘De Corona’ Aeschines was not upheld by the people’s vote.  He retired to Asia, and, it is said, opened a school of rhetoric at Rhodes.  There is a legend that after he had one day delivered in his school the masterpiece of his enemy, his students broke into applause:  “What,” he exclaimed, “if you had heard the wild beast thunder it out himself!”