On the Work of Distinction in Itself

On the Work of Distinction in Itself — St. Thomas Aquinas asks: Whether the word "light" is used in its proper sense in speaking of spiritual things?; Whether light is a body?; Whether light is a quality?; Whether the production of light is fittingly assigned to the first day?.

We must consider next the work of distinction in itself. First, the work of the first day; secondly, the work of the second day; thirdly the work of the third day.

Under the first head there are four points of inquiry:

Article 1: Whether the word "light" is used in its proper sense in speaking of spiritual things?

Ambrose says (De Fide ii) that "Splendor" is among those things which are said of God metaphorically.

Any word may be used in two ways---that is to say, either in its original application or in its more extended meaning. This is clearly shown in the word "sight," originally applied to the act of the sense, and then, as sight is the noblest and most trustworthy of the senses, extended in common speech to all knowledge obtained through the other senses. Thus we say, "Seeing how it tastes," or "smells," or "burns. "Further, sight is applied to knowledge obtained through the intellect, as in those words: "Blessed are the clean of heart, for they shall see God" (Mat. 5:8). And thus it is with the word light. In its primary meaning it signifies that which makes manifest to the sense of sight; afterwards it was extended to that which makes manifest to cognition of any kind. If, then, the word is taken in its strict and primary meaning, it is to be understood metaphorically when applied to spiritual things, as Ambrose says (De Fide ii). But if taken in its common and extended use, as applied to manifestation of every kind, it may properly be applied to spiritual things.

The answer to the objections will sufficiently appear from what has been said.

Article 2: Whether light is a body?

Two bodies cannot occupy the same place simultaneously. But this is the case with light and air. Therefore light is not a body.

Light cannot be a body, for three evident reasons. First, on the part of place. For the place of any one body is different from that of any other, nor is it possible, naturally speaking, for any two bodies of whatever nature, to exist simultaneously in the same place; since contiguity requires distinction of place.

The second reason is from movement. For if light were a body, its diffusion would be the local movement of a body. Now no local movement of a body can be instantaneous, as everything that moves from one place to another must pass through the intervening space before reaching the end: whereas the diffusion of light is instantaneous. Nor can it be argued that the time required is too short to be perceived; for though this may be the case in short distances, it cannot be so in distances so great as that which separates the East from the West. Yet as soon as the sun is at the horizon, the whole hemisphere is illuminated from end to end. It must also be borne in mind on the part of movement that whereas all bodies have their natural determinate movement, that of light is indifferent as regards direction, working equally in a circle as in a straight line. Hence it appears that the diffusion of light is not the local movement of a body.

The third reason is from generation and corruption. For if light were a body, it would follow that whenever the air is darkened by the absence of the luminary, the body of light would be corrupted, and its matter would receive a new form. But unless we are to say that darkness is a body, this does not appear to be the case. Neither does it appear from what matter a body can be daily generated large enough to fill the intervening hemisphere. Also it would be absurd to say that a body of so great a bulk is corrupted by the mere absence of the luminary. And should anyone reply that it is not corrupted, but approaches and moves around with the sun, we may ask why it is that when a lighted candle is obscured by the intervening object the whole room is darkened? It is not that the light is condensed round the candle when this is done, since it burns no more brightly then than it burned before.

Since, therefore, these things are repugnant, not only to reason, but to common sense, we must conclude that light cannot be a body.

Article 3: Whether light is a quality?

Damascene (De Fide Orth. i) says that light is a species of quality.

Some writers have said that the light in the air has not a natural being such as the color on a wall has, but only an intentional being, as a similitude of color in the air. But this cannot be the case for two reasons. First, because light gives a name to the air, since by it the air becomes actually luminous. But color does not do this, for we do not speak of the air as colored. Secondly, because light produces natural effects, for by the rays of the sun bodies are warmed, and natural changes cannot be brought about by mere intentions. Others have said that light is the sun's substantial form, but this also seems impossible for two reasons. First, because substantial forms are not of themselves objects of the senses; for the object of the intellect is what a thing is, as is said De Anima iii, text. 26: whereas light is visible of itself. In the second place, because it is impossible that what is the substantial form of one thing should be the accidental form of another; since substantial forms of their very nature constitute species: wherefore the substantial form always and everywhere accompanies the species. But light is not the substantial form of air, for if it were, the air would be destroyed when light is withdrawn. Hence it cannot be the substantial form of the sun.

We must say, then, that as heat is an active quality consequent on the substantial form of fire, so light is an active quality consequent on the substantial form of the sun, or of another body that is of itself luminous, if there is any such body. A proof of this is that the rays of different stars produce different effects according to the diverse natures of bodies.

Article 4: Whether the production of light is fittingly assigned to the first day?

That without which there could not be day, must have been made on the first day. But there can be no day without light. Therefore light must have been made on the first day.

There are two opinions as to the production of light. Augustine seems to say (De Civ. Dei xi, 9,33) that Moses could not have fittingly passed over the production of the spiritual creature, and therefore when we read, "In the beginning God created heaven and earth," a spiritual nature as yet formless is to be understood by the word "heaven," and formless matter of the corporeal creature by the word "earth." And spiritual nature was formed first, as being of higher dignity than corporeal. The forming, therefore, of this spiritual nature is signified by the production of light, that is to say, of spiritual light. For a spiritual nature receives its form by the enlightenment whereby it is led to adhere to the Word of God.

Other writers think that the production of spiritual creatures was purposely omitted by Moses, and give various reasons. Basil [*Hom. i in Hexaem.] says that Moses begins his narrative from the beginning of time which belongs to sensible things; but that the spiritual or angelic creation is passed over, as created beforehand.

Chrysostom [*Hom. ii in Genes.] gives as a reason for the omission that Moses was addressing an ignorant people, to whom material things alone appealed, and whom he was endeavoring to withdraw from the service of idols. It would have been to them a pretext for idolatry if he had spoken to them of natures spiritual in substance and nobler than all corporeal creatures; for they would have paid them Divine worship, since they were prone to worship as gods even the sun, moon, and stars, which was forbidden them (Dt. 4).

But mention is made of several kinds of formlessness, in regard to the corporeal creature. One is where we read that "the earth was void and empty," and another where it is said that "darkness was upon the face of the deep." Now it seems to be required, for two reasons, that the formlessness of darkness should be removed first of all by the production of light. In the first place because light is a quality of the first body, as was stated (), and thus by means of light it was fitting that the world should first receive its form. The second reason is because light is a common quality. For light is common to terrestrial and celestial bodies. But as in knowledge we proceed from general principles, so do we in work of every kind. For the living thing is generated before the animal, and the animal before the man, as is shown in De Gener. Anim. ii, 3. It was fitting, then, as an evidence of the Divine wisdom, that among the works of distinction the production of light should take first place, since light is a form of the primary body, and because it is more common quality.

Basil [*Hom. ii in Hexaem.], indeed, adds a third reason: that all other things are made manifest by light. And there is yet a fourth, already touched upon in the objections; that day cannot be unless light exists, which was made therefore on the first day.