IL DE ESSENTIIS ESSENTIARUM DEDICATO A ROBERTO, DUCA DI CALABRIA

The aim of this essay is to present the results of a work in progress on De essentiis essentiarum, a two-book treatise on real and intentional essences attributed to Thomas Aquinas and dedicated to Robert, Duke of Calabria. Ever since the time of its composition, De essentiis essentiarum was susceptible to the cutting out of its sections on celestial essences and minerals. These sections also had an autonomous circulation, as did its dedication. The paper focuses particularly on the original redaction, the Urtext – the De essentiis – attempting to reconstruct its structure and tradition. It also provides a transcription of this text, one that is far more complex and interesting than a mere treatise on metallurgical alchemy would usually be.