Anatomical identifications of stars: Textual descriptions in Ptolemy's star catalogue

In this survey paper, we examine the language Ptolemy uses in his star catalogue to describe stars. We focus on anatomical descriptions (more than 700 in the catalogue), i.e., textual entries used to identify objects by relating them to body-parts of imaginary constellation figures. At the syntactical level, by looking at the functional roles of expressions within descriptions, we attempt to reconstruct a general formula to which the great majority of anatomical descriptions conform. We derive statistical results about the relative frequency and variability of various components of our general formula. We also perform a quantitative analysis of the anatomical terms used, and their distributions among specific constellations. We conclude that Ptolemy applies a language that is syntactically formal, in line with both the discursive function and other technical texts of antique geometry, but semantically rich, owing to the anatomical context interplaying with the geometrical one.