In his doxographical work, Lives of Eminent Philosophers, Diogenes Laertius (fl. 2nd century CE) selected three letters that he considered to best summarize Epicurus' doctrine and quoted them in full. While both the Letter to Menoeceus and the Letter to Herodotus contain expected, self-contained, and argumentatively coherent texts, the same cannot be said of the Letter to Pythocles. Surprisingly for a short text that is supposed to deal with the most essential aspects of Epicurus' doctrine, the letter deals with celestial phenomena (τὰ μετέωρα) that at times seem quite remote from the everyday experience of Athenians. Scholars have been able to show that the choice of topics is not only aimed at reassuring people, as Epicurus' ethical agenda would have it. Rather, the letter discusses the "hot topics" of its time (e.g., the size of the sun), reframes them epistemologically, and cleverly interweaves sublunary and superlunary phenomena to dismantle Aristotle's famous division. The text thus actively responds to established scientific knowledge while revealing the ancient reception of new theories.

One particular aspect that has puzzled interpreters for years are the passages in the letter that discuss the so-called ἐπισημασίαι (≈ "signs"). In these passages, Epicurus speaks of the inferences that should not be drawn from the manifestations of "animals" when attempting to predict or explain seasonal and weather changes. It has been suggested that this may actually be a reference to the zodiac, but this has not yet been generally accepted - not least because there is no account of the Epicurean view of the zodiac to support it. 

The aim of this exploration is to provide such an account and to evaluate all the relevant textual evidence available. Synchronically, the Epicurean reception of the zodiac is entangled in a series of epistemological arguments concerning the certainty of knowledge and the modality of its acquisition and validation. Diachronically, it is entangled in a network of interpersonal relations, religious contexts, and literary agendas. 

In collaboration with the ZODIAC project team, both the synchronic and diachronic axes will be investigated. In this way, the project will also contribute to mapping the proliferation of the zodiac as a hermeneutical and argumentative timeframe across ancient cultures and contexts. Namely, why this interpretation of (celestial) time became so successful and, at least for some philosophers, so problematic.