In a part of his work On Poetry, Philodemus spends 170 columns (around 18,000 words) rebutting the theories of Heracleodorus. There is also little doubt that Lucretius would have been aware of Heracleodorus' arguments. Reading through Janko's summary of Heracleodorus' ideas shows that there was a lot to object to:
(i) Genre, and the diction and content peculiar to genre, do not matter for poetic excellence; for the pleasure of poetry comes from composition rather than from language or content, which are shared with others. In fact, mimes like Sophron's are said to be poems; since even good prose-writers, like Demosthenes, Xenophon, and Herodotus, are actually poets, metre is irrelevant.
(ii) The contents of poetry, even including raw materials as ugly as fish, chamber-pots, or garlic, are irrelevant to composition, as is seen in passages from Archilochus, Sophocles, and Euripides. This is because content is irrelevant without good composition, and becomes beautiful from the particularity of the elaboration; good content need not entail good composition, as witness Chaeremon. So long as content is well composed, it may be shared or invented, or even false or unrecognizable, as Euripides shows. Artistry can redeem incomprehensible content. Poetry, like metalwork, needs artistry; composition, not raw material, is its particularity.
(iii) Obscurity can be good if the composition is good, as witness the minor tragedian (Anti)philus as compared with Hipponax and Empedocles, who also wrote tragedies. Homer entices us with his unclear proems, and poetic words are enthralling even if they are obscure, as many examples in Homer and Alcaeus prove. It is sound, not content or diction, that benefits verses. Different craftsmen, like ring-engravers and writers, use different materials, but all aim at achieving excellence in representation by means of their different media.
(iv) Excellence lies not in the composition but in the euphony that supervenes upon it, as is proved by rearrangements of the words in verses from poets such as Homer. Such metatheses prove that diction, word-choice, or content do not create beauty. Since sound, not content like plot or character, determines which verses are superior, as witness Choerilus and Anaximenes when compared with Homer, word-choice or content is not the cause of sound. Even prose-writers aim not at truth, but at pleasure, and poets must please the many by applying vivid new words to difficult contents; such words shine brightest when they first appear, like purple garments. The imitation of content must contribute to euphony via majestic and opulent diction, even if the poet utters total absurdities; but the choice of Homeric words does not by itself create the musical sonority that Heraclides desiderated.
(v) Plot depends on the poet's excellence, as we can see from Homer and Archilochus; bad poets often attempt fine plots, but fail to construct them well. Character too depends on the poet's excellence, which enables him to depict men, women, slaves, and animals without becoming comic or iambic. Not content, but excellence in composition, is the particularity of poetry; pleasing composition of diction that vividly, suggestively, clearly, and concisely expresses the underlying meaning is excellence, provided that it maintains poetic style and is suited to the genres, as poets do not prefer clarity to the tragic manner. Critics wrongly claim that the particularity lies in composition that conveys clever, beneficial, or exceptional content, or in character, but character does not determine excellence; composition is its sole cause. Excellence depends not on content, diction, or accidence, but on composition as necessitated by the sounds; when vividness creates excellence, it relies on sound. Critics wrongly claim that verse depends on its material and its writer, his diction and his thought.
(vi) The representation of intelligible content is related to genre, as witness epic style, which contains all the genres. However, genre is irrelevant to excellence, whether we compare Homer to Archilochus, Euripides, or anyone else; rather, it is excellence that creates style, if not also genre.
