Lionardo Di Capoa’s Parere is just that: an opinion in response to a specific request by the Viceroy and the Consiglio Collaterale in 1678 put to a group of prominent Neapolitans for counsel on a legal regulatory policy; at the behest of his friends it was expanded for publication in 1681, then revised in 1689. Di Capoa was noted for his polymathy, and had a polymathic formation; he began as a student of law, switched to medicine at his friends’ urging, spent a period of rustication in Capoa both in literary pursuits (writing over 2,000 Petrarchan sonnets), and, in Democritean fashion, anatomizing innumerable animals. Returning to Naples to publish the sonnets, he was robbed of both sonnets and horse, and took up medicine again, functioning, with Tommaso Cornelio, as a principal of the Accademia degli Investiganti; later, like Cornelio, he gave up the practice of medicine for the sole pursuit of ‘natural philosophy’. He was the recognized leader in private instruction in chemistry (there was no university instruction). 1