Magnesia catholica

Meaning

Magnesiam Catholicam is a learned name for the matter described as the seed of the whole world and source of natural things. In this setting ‘universal’ is the relevant force of catholica; the phrase is not a reference to ecclesiastical affiliation. The surrounding description combines one matter, several numerical formulations and a balance of elements.

The English presents the normalized title ‘Magnesia catholica’, while the historical phrase is inflected as Magnesiam Catholicam. No identification with a modern substance sold as magnesia follows. Its lexical function is one name within a deliberately manifold account of the matter, not a modern chemical specification.