Lodovico Castelvetro (ca. 1505 in Modena – 1571 in Chiavenna) was an important figure in the development of neo-classicism, especially in drama. It was his reading of Aristotle that led to a widespread adoption of a tight version of the Three Unities, as a dramatic standard.
His Poetica d'Aristotele vulgarizzata e sposta ("The Poetics of Aristotle translated in the Vulgar Language and commented on") was called the most famous Italian Renaissance commentary on Aristotle's Poetics. His supposed involvement in translation of Protestant texts caused him trouble with the Church. He was labelled a heretic in 1557, and lived in exile from his native Italy (he was born near Modena). His Giunta, a commentary on the Prose della volgar lingua by Pietro Bembo, is one of the earlier texts on Italian grammar, and linguistics in general; his contemporaries objected to him that his theories were a little too philosophical for their time.
Castelvetro published some remarks on the language of Annibal Caro which led to some fierce debates; as an outcome of these disputes, a certain Alberigo Longo from Salento was killed, perhaps by the same Castelvetro, because his courage matched his erudition. Benedetto Varchi was involved, albeit reluctantly, in this dispute; he speaks of his involvement in the Ercolano, one of the books which are dearest to the lovers of the Florentine tongue.
Castelvetro contradicts Aristotle on a number of issues. He did not advocate the unity of action, the only unity Aristotle felt to be essential.