Now, if we reflect on this at all, we clearly see that God formed them in relation to the properties of light, or in relation to the action of ethereal matter, of which He is also the creator and mover, so that, with God always acting in the world in a uniform and constant manner through the general law of the communication of motion (for the transmission of rays and their different refractions is a consequence of it) and in our souls through the general law of their union with the body,.e., according to what reaches our brain through our eyes, we might be sufficiently advised for the good of society and preservation of life, of the presence of, and the differences in, all the objects surrounding us.