On Light

Robert Grosseteste

Published: 1225

Description:

T light. HE first For corporeal light a'f its form very which nature some diffuses caU corporeityl itself in every is in direction my opinion in such a way that a point of light will produce instantaneously a sphere of light of any size whatsoever, unless some opaque object stands in the way. Now the extension of matter in three dimensions is a necessary con· comitant of corporeity, and this despite the fact that both corporeity and matter are in themselves simple substances lacking all dimension. But a form that is in itself simple and without dimension could not introduce dimension itt every direction into matter, which is likewise simple and without dimension, except by multiplying itself and diffusing itself instantaneously in every direction and thus extending matter in its own diffusion. For the fonn cannot desert matter, because it is inseparable from it and matter itself cannot be deprived of form.-But I have pro- posed that it is light which possesses of its very nature the function of multiplying itself and diffusing itself instantaneously m all d,rectIOns. Whatever perfonns this operation is either light or some other agent that acts in virtue of its· participation in light to which this operation belongs essentially. Corporeity, therefore, is either light itself or the agent which performs the aforementioned operation and introduces dlmenslOns mto matter in_ virtue of its participation in light, and acts through the power of this same light. But the first form cannot introduce dimensions into matter through the power of a subsequent form. Therefore light is not a form subsequent to corporeity, but it is corporeity itself. ,

[maintain]