For on the first day God created earth and water mingled together—that unformed, unordered mass of bodies which Moses calls tohu va-bohu, earth empty and void—as the foundations of the world. On that same day he immediately added light, since “light is the first grace of a building,” as Ambrose says concerning Genesis 1:3–5. This light, like the later light already discussed, was no substance, nor an incorporeal one, as those suppose who would understand it as the element fire, the sun, or a luminous little cloud. In agreement with sounder thinkers, I hold that it was an accident: a certain transparency and translucency, or luminous quality, not subsisting without a subject but inhering in one.

On the first day of creation it inhered in the surface, or in some subtler part of the waters; on the second and third days, in the air or the whole expanse of the heavens; finally, on the fourth day, after the luminaries had been created in heaven, it was imparted to the sun, moon, and other stars.

Second, light may be ordinary: that which arises and spreads from the sun, moon, and other heavenly bodies, illuminating the world and every body wherever no intervening obstruction removes its radiance. I consider this opinion reasonable and worth setting down. I have no intention of prescribing your judgment by it, and so forth.

Second Letter Reverend Sir, I have received the letter with which you honoured me. I had not intended to dispute with you the question we raised about light, whether it is a substance or an accident. But after seeing the plausible arguments advanced in your letter to maintain the denial of the former, I decided to change my mind and intention. I do not presume to instruct someone more learned; I simply do not wish to pass over so welcome an opportunity to contemplate God’s works.

To address the matter itself, I shall first answer very briefly your objection to the major premise of my earlier syllogism. You consider it only particular, since accidents too are created by God, and adduce the example of God’s image “created together with man,” to use your own words. But this does not follow. Accidents can be said to be created only in a relative sense. We must distinguish things created from things created together with something else; an inference drawn indiscriminately from these different classes is unsound. I shall say nothing of the fact that the controversy about the image of God has not yet been settled.

I therefore set out and repeat the following syllogisms: Whatever is created through the Word of God is a creature. Light is created through the Word of God. Therefore light is a creature. Further: Every creature is a substance. Light is a creature. Therefore light is a substance.

The major premise of the first syllogism is self-evidently true, and you yourself acknowledge that its minor premise is sufficiently proved from Holy Scripture, Genesis 1:3. From these points, the major premise of the second syllogism likewise appears self-evidently true and clearer than the sun itself. All these arguments are also excellently supported by the words of that most deserving theologian Johann Arndt:

“The Word that God spoke in creation did not vanish, but became the life of all creatures.” This shows not only that whatever is created through God’s Word is a creature and consequently a substance. One may also rightly argue: if God’s Word became the life of every creature, it became the life of light as well; therefore light has life. Further, if light has life, it has form; if it has form, it too is a substance.

Indeed, God’s Word is that proper form which from the beginning of creation gave, and still gives, existence to all things. Almost all the ordinary philosophers began stammering about this form many centuries ago and still stammer about it. Sometimes they multiply words, yet they do not themselves know what their form is, as that inquisitive Sp., together with his most subtle Sc., frankly admits. One may therefore rightly say that they hand their students words in place of things and terms in place of philosophy.

To answer also as to syllogistic form, I grant the major premise of both your first and your second syllogism, although they seem to hold more in logic than in natural philosophy. But I deny the minor premises of both. The contrary—that light inheres in no body but subsists in and through itself—is proved by Job 38:19: “Where is the way in which light dwells, and where is the place of darkness?” From this I argue: Whatever does not inhere in a body is not an accident. Light does not inhere in a body. Therefore light is not an accident.

The major premise is your own proposition. The minor is proved not only by what has been said, but also by the fact that you have proved nothing, although the burden of proof always rests on the person making the assertion. First, you claim that light exists in fire, in the sun and stars, or in some other body. Second, you object that light is not a substance because it is neither corporeal nor incorporeal. Third, by way of explaining or clarifying your meaning, you say that light in its proper and natural sense is intended, and divide it into extraordinary and ordinary light, as your letter sets out at greater length. None of this proves anything, since proofs must be conclusive.

As to the first point, fire itself can neither exist nor even be conceived without its own subject, as de Nuysement, that most ingenious Hermetic philosopher, attests; experience too can demonstrate it. Thus either fire is not a substance, or your arguments are not unconditionally true. It is absurd that something which cannot exist without a subject should itself be the subject of something else.