Light Works, Light and Film
" Lux was God-given, essential light, the being of light and as such a reflection of its Maker. Augustine viewed it as the simplest, noblest, most mobile and diverse of all corporeal being. Lumen, by contrast was the material means by which our perception of the being of light (as lux) arose. When we sense the brilliance of the sun, we are percieving its lux, but we do so by means of the unseen lumen that connect it to us. Between the time of Augustine and galileo, the being of light that ensouled space (lux) retreated, leaving behind its hard material vestige (lumen) as a fossil record for the curious natural philosopher'