Of God and His Creatures

Corpora indivisibilia, so the Editions. But the Bergamo autograph, if we may trust the printers, has corpora invisibilia. That a body may have accidents impervious to sense, a microscopic composition quite other than what appears to the eye, does not seem usually to have been recognised by the schoolmen. Their 'accidents' are the sensible phenomena of bodies. Here again the progress of physics has seriously affected metaphysics. The use of reading a mediaeval book about 'accidents' is to enable you to understand mediaeval authors and to interpret mediaeval formularies. But when you have caught the meaning, it remains for you to apply it to the ulterior conditions revealed by later science, -- no easy task.

Of God and His Creatures: 3.65