He was mild and dignified of aspect.
Some of these works are in the style of comedy, for instance the tracts On Pleasure and On Temperance; others in the style of tragedy, as the books entitled Of those in Hades, Of Piety, and Of Authority.
Again, he has a sort of intermediate style of conversation which he employs when philosophers, generals and statesmen converse with each other. 89. Furthermore, he wrote geometrical and dialectical works, and is, besides, everywhere versatile and lofty in diction, and a great adept at charming the reader's mind.
It seems that he delivered his native city from oppressions by assassinating its ruler, as is stated in his work on Men of the Same Name by Demetrius of Magnesia, who also tells the following story about him: "As a boy, and when he grew up, he kept a pet snake, and, being at the point of death, he ordered a trusted attendant to conceal the corpse but to place the snake on his bier, that he might seem to have departed to the gods. 90. All this was done. But while the citizens were in the very midst of the procession and were loud in his praise, the snake, hearing the uproar, popped up out of the shroud, creating widespread confusion. Subsequently, however, all was revealed, and they saw Heraclides, not as he appeared, but as he really was."
I have written of him as follows:
You wished, Heraclides, to leave to all mankind a reputation that after death you lived as a snake. But you were deceived, you sophist, for the snake was really a brute beast, and you were detected as more of a beast than a sage. Hippobotus too has this tale.
91. Hermippus relates that, when their territory was visited by famine, the people of Heraclea besought the Pythian priestess for relief, but Heraclides bribed the sacred envoys as well as the aforesaid priestess to reply that they would be rid of the calamity if Heraclides, the son of Euthyphro, were crowned with a crown of gold in his lifetime and after his death received heroic honours. The pretended oracle was brought home, but its forgers got nothing by it. For directly Heraclides was crowned in the theatre, he was seized with apoplexy, whereupon the envoys to the oracle were stoned to death. Moreover, at the very same time the Pythian priestess, after she had gone down to the shrine and taken her seat, was bitten by one of the snakes and died instantly. Such are the tales told about his death.
Autodorus the Epicurean criticizes him in a polemic against his tract Of Justice. Again, Dionysius the Renegade, or, as some people call him, the "Spark," when he wrote the Parthenopaeus, entitled it a play of Sophocles; and Heraclides, such was his credulity, in one of his own works drew upon this forged play as Sophoclean evidence. 93. Dionysius, on perceiving this, confessed what he had done; and, when the other denied the fact and would not believe him, called his attention to the acrostic which gave the name of Pancalus, of whom Dionysius was very fond. Heraclides was still unconvinced. Such a thing, he said, might very well happen by chance. To this Dionysius, "You will also find these lines:
a. An old monkey is not caught by a trap. br> b. Oh yes, he's caught at last, but it takes time."
And this besides: "Heraclides is ignorant of letters and not ashamed of his ignorance."