[3] He was criticized by Philodemus in his book on poetic theory written around the 1st century BCE, and was also the target of a work by the obscure writer Aristocritus titled Positions Against Heracleodorus, which is mentioned by the 2nd century theologian Clement of Alexandria.
[1] The information we have about him is scant, so it is not entirely clear what even Heracleodorus's positions were what so irritated critics across the centuries.
[1] We know he was a comparatively radical "euphonist" (that is, he believed the thing that mattered most was how poetry sounded) and anti-genre critic, who favored erasing genre boundaries around the art.
[4] Scholars have described the quotations we do have -- given by hostile critic Philodemus -- as mostly being rendered without context, and what we do have suggests they have at least some views in common, for example that artistic and moral judgments were separate (that is, it is possible to write a good poem about bad things).
Heracleodorus apparently believed that audiences could and would be legitimately moved by poetry without always fully understanding what was going on.