Plutarch Alexander 19

[1] Dareius was still more encouraged by Alexander’s long delay in Cilicia, which he attributed to cowardice. The delay was due, however, to a sickness, which assailed him in consequence of fatigues, according to some, ¹ but according to others, because he took a bath in the river Cydnus, whose waters were icy cold.

[2] Be that as it may, none of the other physicians had the courage to administer remedies, but thinking that the danger was too great to be overcome by any remedy whatever, they were afraid of the charges which would be made against them by the Macedonians in consequence of their failure; but Philip the Acarnanian, who saw that the king was in an evil plight, put confidence in his friendship, and thinking it a shameful thing not to share his peril by exhausting the resources of art in trying to help him even at great risk, prepared a medicine and persuaded him to drink it boldly, if he was anxious to regain his strength for the war.

[3] Meanwhile, however, Parmenio sent a letter to Alexander from the camp, urging him to he on his guard against Philip, for the reason that he had been persuaded by Dareius with the promise of large gifts and a marriage with his daughter, to kill Alexander. Alexander read the letter and placed it under his pillow, without showing it to any one of his friends. When the time appointed was at hand, and Philip came in with the king’s companions, carrying the medicine in a cup, Alexander handed him the letter, while he himself took the medicine from him with readiness and no sign of suspicion.

[4] It was an amazing sight, then, and one well worthy of the stage,—the one reading the letter, the other drinking the medicine, and then both together turning their eyes upon one another, but not with the same expression; for Alexander, by his glad and open countenance, showed his good will towards Philip and his trust in him, while Philip was beside himself at the calumny, now lifting up his hands towards heaven and calling upon the gods to witness his innocence, and now falling upon the couch on which Alexander lay and beseeching him to be of good courage and obey his physician.

[5] For at first the medicine mastered the patient, and as it were drove back and buried deep his bodily powers, so that his voice failed, he fell into a swoon, and became almost wholly unconscious. However, he was speedily restored to his senses by Philip, and when he had recovered strength he showed himself to the Macedonians, who refused to be comforted until they had seen Alexander.