Why this Question Matters.
“And God said, ‘let there be light’ and there was light. And God saw that the light was good; and God separated the light from the darkness. God called the light Day, and the darkness He called Night. And there was evening and there was morning, one day.”
The work of the first day of creation involves the creation of light and the separation of light from darkness; in doing this, day and night come to be. But what is this light? Is the creation account here simply a pre-scientific account of the coming to be of photons? Is this an account of the coming to be of only the material world or are there spiritual aspects involved as well? If we recall from the previous question that it was commonly taken that the first four things to be created were the angelic nature, the empyrean heaven, unformed corporeal matter and time, how is light connected with these?
When we read the opening words of Genesis, we must be aware of the different meanings associated with light throughout the scriptures; one might at least turn to the Gospel of John, for example. Amongst the Church Fathers, the majority position was that the account of creation given here is an account of the creation of the material world. But St Augustine interpreted the account in a different way; as the creation of the spiritual natures. In this question, as it leads up to its conclusion in the final article, Aquinas gives equal account to these different approaches, without judging between them.
The Thread of the Argument
A1: If we recognize that the light referred to in the creation account of Genesis may mean more than simply material light, then the question that Aquinas addresses in the first article will seem apposite; can light properly be said to exist in spiritual things?
Aquinas recalls that in our use of language a term may have a primary meaning that is expanded in actual use. So a word such as “vision” primarily refers to an act of the sense of sight but has secondary usages that go way beyond this primary usage. Not only do we extend the use of the word to other senses (“see how hot this iron is”) but even to intellectual vision (“I see what you mean”) and to the beatific vision (“Blessed are the pure of heart, for they shall see God”). This analysis applies to the term “light”; its primary meaning attaches to the illumination that facilitates the sense of sight, but its extended meanings apply to whatever provides the illumination for any type of knowing.
So, if “light” is taken in its primary meaning, applying it to spiritual creatures is a metaphor rather than a proper usage; but if we take it in its extended meaning, then it is properly applied to spiritual creatures.
A2: If we now restrict our attention to light considered in its primary meaning as that which facilitates the sense of sight, determining the nature of light is still a fascinating and enduring question. In an amusing parallel to the modern debates over the wave versus particulate nature of light, the objections and the sed contra of this article observe that in some ways light acts like a material body but in other ways it does not.
Aquinas argues that it is quite wrong to think of light as a body; and for this he gives three arguments. In the first place, material bodies occupy space and it is impossible for two material bodies to be superposed, whereas light can be superposed. Secondly, according to the physical understanding of the day, illumination occurs instantaneously and therefore light cannot be the translation of a material body. Finally, if air were a material body, a composite of matter and form, then we would have to think of the passing from light into darkness in terms of the corruption of the body of light into another substance. Why ever would light corrupt simply because of the absence of a source of light?
A3: If light is not a body in the sense of being a material substance, then what is it? Aquinas turns to the Aristotelian understanding of the modes of being laid out in the Categories and argues that light is a quality, one of the accidental categories of being. He makes the analogy between heat and light, observing that heat is a quality derived from the substantial form of fire; it is an accident that follows on necessarily from the being of fire. Likewise light is a quality that follows on from the substantial form of the sun (or from any other self-illuminating body).
In arriving at this conclusion, Aquinas considers and rejects a number of alternative explanations. Light cannot have a merely intentional being (that is, existing only in the mind), as intentional beings cannot cause physical changes in the way that light does. Light is not the substantial form of the sun, as substantial forms cannot be directly perceived in the way that light can be; nor could light then exist in air, as substantial forms make whatever they inform to be what they are.
A4: The first three articles have concluded that we may properly associate light with spiritual creatures, provided that we take the term light in its extended sense, and that if we restrict it to its primary meaning then we must consider light as a quality rather than as a body. However, when we turn to the text of scripture, this position would appear to imply some serious difficulties. If light is a quality, then it is an accident which has to be an accident inhering in some substance; but what is that substance? Scripture has not spoken of it. Similarly, a consideration of the next few days of creation suggests that placing the creation of physical light on the first day is incoherent. For example, light distinguishes day from night; but this is associated with the sun which is not created until the fourth day. Similarly, night and day would appear to be inextricably associated with the firmament, which was made on the second day. Even if one takes light as referring to the creation of spiritual creatures, there is still a problem: in the beginning there was no spiritual darkness to be separated from the light as all the spiritual creatures were created good.
In his answer, Aquinas alludes both to the singular approach of St Augustine to the book of Genesis, in which the opening verses are taken to refer to the creation of spiritual beings, as well as to the majority opinion in which these verses are taken as referring to the creation of the material world. In Augustine’s approach when scripture says that “God created heaven and earth”, this means that God created the spiritual creatures (heaven) and the material creatures (earth). The production of light on the first day then corresponds to the production of the spiritual light that illuminates the minds of the spiritual creatures. The fourth objection is answered by observing that Augustine does not take this sequence of events described in Genesis as a temporal sequence. All the events of the fall of the bad angels take place in the (temporal) instant of creation; the sequence of the narrative represents the ontological priority of the events and not any temporal priority.
To others of the Church Fathers, the account of Genesis omits description of the creation of spiritual creatures for a number of reasons. For them, the account of Genesis is an account of the creation of the material world. In that account, Aquinas argues that the creation of light is appropriate to the first day for two reasons. On the one hand, light is a quality that inheres in all bodies; in particular it must inhere in the primeval matter that comes to be in the first instant of creation. On the other hand, light is what makes manifest the work of creation and therefore it is fitting that such light be present at the beginning of creation.
In answering the first three objections that relate to the creation account as the creation of the material universe, Aquinas takes the position that the unformed matter created on the first day is not unformed in the technical hylomorphic sense. Rather it is created informed by primeval substantial forms that will be replaced by other, more organized, forms later in the days of creation. Therefore it is perfectly consistent to say that the light of creation is a quality of this primeval matter. Similarly, the light of creation can be taken to be the light of the pre-formed sun; the illumination from this is an illumination in a general sense rather than in the specific ways that the actual sun provides. Likewise, one may associate night and day in a specific way with the motion of the firmament but one can also associate it in a general way with the primeval forms that will later become the firmament.
- Words have primary meanings and extended meanings. The word light in its primary meaning can only be applied metaphorically to spiritual creatures; but in its extended meaning it can be properly applied to them.
- Aquinas, guided by the scientific understanding of the day, concludes that light is not a body but is a quality; the latter being one of the accidental categories of being.
- Light was created on the first day as light inheres in all created bodies, including the primeval matter of the first day. Also it was fitting that light was present so early in creation in order to manifest the work of creation.
- The association of light with various forms that were created later in the six days is anticipated by its association with the primeval matter of the first day.
- The arguments of the second and third articles appear to fall apart in the light of modern physics. However, these two articles are really only used as preliminary lemmas leading up to the main result of this question in the fourth article. It would not appear too difficult to reconstruct the conclusion of the fourth article in the light of modern scientific understanding.