Joshua's reference to DeWitt's article on the history of Roman Epicureanism leads to this, on Posidonius, the Stoic of Roman period (died 51 BC) who embraced astrology. This is of course relevant to Epicurean philosophy's rejection of all sorts of divination, traceable to Epicurus himself, but which position would have been more relevant if promoted by Stoics like Posidonius.
It was not the multiplication of its rivals, however, nor their combination, nor sumptuary laws, nor even the disorder of civil wars, that finally destroyed Roman Epicureanism as a distinctive movement. These were hostile influences, of course, but the real solvent was the irresistible Roman tendency to syncretism, which is much preferable to the term eclecticism. The latter distinctly implies the act of choosing, which is falsely assumed. For example, Posidonius did not choose out the Stoic belief in fate as an element of the Stoic creed which might be combined with astrology. The process was quite different. Practice preceded synthesis. The Stoic belief in fate had been held in certain Roman circles for a century. The practice of astrology grew up alongside of it. Syncretism took place in spite of the philosophers, and all they could do was to acknowledge it. Philosophy, like theology, often pretends to lead the procession, when in reality it follows it.
From Wikipedia on Posidonius:
The philosophical grand vision of Posidonius was that the universe itself was interconnected as an organic whole, providential and organised in all respects, from the development of the physical world to the behaviour of living creatures. Panaetius had doubted both the reality of divination and the Stoic doctrine of the future conflagration (ekpyrosis), but Posidonius wrote in favour of these ideas. As a Stoic, Posidonius was an advocate of cosmic "sympathy" (συμπάθεια, sympatheia)—the organic interrelation of all appearances in the world, from the sky to the Earth, as part of a rational design uniting humanity and all things in the universe. He believed valid predictions could be made from signs in nature—whether through astrology or prophetic dreams—as a kind of scientific prediction.
The Wikipedia article includes that David Sedley also says Posidonius drew on Plato and Artistotle:
He [Posidonius] followed not only the earlier Stoics, but made use of the writings of Plato and Aristotle. Posidonius studied Plato's Timaeus, and seems to have written a commentary on it emphasizing its Pythagorean features. As a creative philosopher, Posidonius would however be expected to create innovations within the tradition of the philosophical school to which he belonged. David Sedley remarks:
QuoteOn the vast majority of philosophical issues, what we know of both Panaetius and Posidonius places them firmly within the main current of Stoic debate. Their innovatively hospitable attitude to Plato and Aristotle enables them to enrich and, to a limited extent, reorientate their inherited Stoicism, but, for all that, they remain palpably Stoics, working within the established tradition.
So Roman Epicureans at the time Cicero was writing his Torquatus material in both "On Ends" and "On The Nature of the Gods" would have reason to have been recently confronting claims by at least some Stoics of the validity of astrology.