The etymology relies on the principle that the starting point may be a syntagm rather than a word, with which it combines the usual phonetic manipulation of epenthesis: from hē onēsis (definite article + noun) one gets a new word *hēonē, and then hēdonē via the insertion of a consonant, [d] (based on the observation that the conjunction δὲ indeed can be inserted between the article and the noun). Dropping of the final syllable is assumed but not explicitly. This explanation does not take into account the morphological boundary between article and noun: rather, the article is used here to justify the initial [hē] of the considered word: Greek lexicographers almost never proceed that way, and Plato here departs from the etymological practice known to us from later sources