Aquinas and what God is not

Medieval Christian Experience Essay 2021

Thomas Aquinas was a medieval scholar and an integral figure in the development of Western philosophy, particularly for the Catholic Church and the development of Christian apologetics. He is also well known for his natural theology. Natural theology, also referred to as natural philosophy, is an investigation into the existence, nature and attributes of God by referring to history, reason and empirical science, as opposed to an appeal to revelation and tradition. This, therefore, is a discussion that even the nonbeliever can participate in. In his “Five Ways,” Aquinas draws on observations about the world in order to demonstrate the existence of God. Of particular significance is his argument that God is the first efficient cause of all things, and it is from this judgement that Aquinas would demonstrate how one might talk about God’s nature. Aquinas reasons that God can be known through causality, negation and transcendence. Due to God’s incomprehensibility, man can only say what He is not, however, it is also possible for man to make true statements about what God is by observing the creatures that He has caused to exist. Aquinas combines negative and positive theology, in which the latter is primary, yet must be corrected by the former.

To better define the concept of natural theology, Aquinas differentiates between two kinds of truth. On the one hand, there are some truths about God that “exceed all the ability of human reason.” Such truths cannot be discovered and understood through reason alone, nor through any solely human endeavour. These include the majority of theological truths, such as the incarnation and doctrine of the Trinity, and are knowable through faith, grace and divine revelation. On the other hand, there are some truths about God which are knowable through natural reason – most centrally, that God exists. These truths can be discovered and reasoned about from within the limits of the human intellect. Here, Aquinas makes a distinction between the “mysteries of the faith” (inaccessible to human reason) and the “preambles of the faith” (knowable by reasoning about experiential things). These mysteries surpass, but do not conflict with, that which can be known via human reason.[1] The relevant distinction is that theology explores revealed truths about God, while natural theology concerns that which can be known using reason alone. Natural theology does not appeal to Christian faith nor scriptural authority, instead inquiring into observable, empirical data.

“The Five Ways” constitute a well-known and important element of Aquinas’ natural theology. Aquinas, by observing the natural world, begins with necessary facts about the universe (as he saw them) and reasons backwards that this fact is an effect with a cause, which is God – that is, he makes an a posteriori argument to prove the reality of God. These arguments are briefly summarised as follows. The first four ways are known as the cosmological arguments. In his Argument from Motion, defining God as the Unmoved Mover, Aquinas observes that movement is caused by movers. Knowing this, something must have started a chain of movement at the beginning, otherwise there would be an infinite regress and no beginning – Aquinas saw such a regress as absurd. There must have been a time where nothing was in motion, and as such, there must have been an immovable first mover – and this, Aquinas claimed, is God. The second way is structurally similar to the first and will be addressed below. The third way, the Argument from Contingency, observes that there are contingent (unnecessary/dependent) things – things that did not need to exist. If everything is contingent, then there must have been a time in which nothing existed. However, things exist, so there must be a necessary and self-sufficient being which contingent beings depend upon – and this is God. Aquinas’ fourth way, the Argument from Degrees of Perfection, reasons simply that in order for there to be degrees of perfection, there must be a perfect standard against which everything else is measured – and this is God. Finally, the fifth way, the Argument from Design, insists that things of the natural world appear to be designed with a purpose/teleology, and this implies an intelligent designer, which is God.

The second way, the Argument from Efficient Causes, is straightforward and particularly relevant here. One might summarise it as follows (Floyd, n.d., Brown n.d.):

1. In the sensible world, there is an “order of efficient causes.”

2. Nothing can be the efficient cause of itself, or else it would be metaphysically prior to itself, which is impossible. (Nothing can come from nothing.)

3. Every efficient cause appears to have a prior cause.

4. To remove the cause is to remove the effect. (No first cause = no intermediate causes or ultimate effect.)

5. Therefore, there cannot be an infinite regress of causes.

6. There must be a first cause “to which everyone gives the name of God.”

It is important to note that Aquinas is not so interested in the temporal ordering of causes as he is in the metaphysical / ontological ordering – that is, things depend upon God, who causes them to exist at any time. Aquinas refers to a “hierarchy of causes, in which a subordinate member is here and now dependent on the causal activity of a higher member” (Copleston, 1955: 122). These Five Ways do not disclose anything of theological merit, only showing that God, in some form and sense, exists. Aquinas’ natural theology demonstrates that God is, but not what God is. In reasoning about God’s nature, Aquinas takes and integrates two approaches to talking about and ascribing attributes to God. These are the way of negation (via remotionis – describing God’s nature in terms of what He is not) and the way of affirmation (via affirmationis – describing God’s nature in positive terms).

To prove that God exists must be established prior to a discussion over His nature. Aquinas argued that we can demonstrate His existence using the Five Ways, however it is not so clear whether we can know more of God, for His nature surpasses man’s ability to understand. In describing how one should talk about God, Aquinas seems to argue for a complex balance between negative (via remotionis) and positive (via affirmationis) theology, of God’s unfathomable essence and the ability of man to use analogy to make true statements about Him (Rocca, 1993). That is, in “God-talk,” man can only speak of God in terms of what He is not or in terms of the perfections God causes creatures to have (Floyd, n.d.). Aquinas’ Five Ways, particularly his Argument from Efficient Causes, lay the groundwork for this unique balance. By starting from material things, of which man can have some understanding, man can acquire knowledge concerning the nature of immaterial things, which transcend understanding.

Aquinas has historically been regarded as an empiricist, being of the view that man acquires knowledge through sensory experience of material things. God, however, is immaterial, and therefore His nature is unknowable. In the sensible world, there is an ordering of efficient causes and an uncaused first cause, which we call God. To Aquinas, words symbolise concepts, which are the “likeness of things.” Man cannot grasp the essence of God because our concepts are derived from the material world, and such concepts fall short of the reality of God – there is nothing for one to compare Him to, and any name we use is lesser than what He is. God’s incomprehensible nature is what makes the method of negative theology necessary in order for man to say anything about Him. Certainly, man must be able to say things of God, for this is something that Biblical authors do, and to propose that these men were wrong to describe God at all is controversial in the Church, to say the least. Aquinas also believed that God could be named by His creatures because He is their cause (Davies, 1993). Aquinas argues that while man cannot know what God is, man can use natural reason to determine what God is not, by denying that which is incompatible with the conclusions of the Five Ways.

Starting from the understanding that things are caused, and caused things have parts, one can describe a number of things that can be known about God, through the negative approach. Material things have individuating accidents, and all caused things exist on account of some external cause. God is not an individual, in the sense that He is not a member of a class/species of which are numerous members that share a common nature. Unlike creatures, God does not have a nature, He is His nature. God is uncaused, and therefore He does not have parts – that is, He is metaphysically simple. God is not a collection of attributes, in fact, technically, He does not have attributes. As a simple being, there must be no unrealised potential in Him, God must be wholly actual, and therefore, perfect (Floyd, n.d.). Creatures are potentially non-existent and dependent upon God, who does not have existence, but is His existence. God cannot be distinguished from His nature, nor can He be distinguished from His existence, for His existence is not derived from another (Davies, 1993). We therefore know that God is not changeable, for if God were to have some quality at one time and a different quality at another, then He would be composed of substantial and accidental parts. From this, we can know that God is not a temporal being, for time measures change (Brown, n.d.).

By modern scholars, Aquinas is often regarded as “agnostic,” in the sense that, at the fundamental level, he argues that man cannot know God truly. It is important to consider that Aquinas also used a kind of positive theology in order to talk more about God’s nature. By knowing that God is the first efficient cause and knowing what He is not, man can know God by way of excellence. This method is possible because, to Aquinas, effects resemble their causes – that is, causes express their nature in their effects. Therefore, causes can be known via their effects, in a similar sense as to how alcohol can be known via a drunk person (Davies, 1998). Perfections that exist in effects must exist, in a superior sense, in its cause – otherwise these perfections would be uncaused and could not exist. In God, as the ultimate cause of all things, must pre-exist all the perfections of creation in a more excellent way. Man can know God from His effects. It must be understood that effects are lesser than, and inadequately represent, their causes. This is because they are of different kinds, and while God is wholly simple, creatures are composites – God does not share the limitations of creatures. It is for this reason that attributes cannot be applied univocally to God and creature (that is, they cannot share the same exact meaning in each case).

Here, we describe Aquinas’ “doctrine of analogy,” that man can describe God and creatures analogically. To Aquinas, man’s literal ways of describing God must be either univocal, equivocal, or analogical. He rejects univocity[2] because it reduces God, ignoring the sense that He is incomprehensibly transcendent and unlike creatures in many ways. Additionally, Aquinas rejects equivocity[3], for this would imply that man could know nothing about God at all, and he has already demonstrated that man can indeed know some truths about God. The remaining means of describing God is analogical, which make true propositions about God without truly understanding what these mean as they are applied to Him.

Aquinas maintains that attributes used analogously of God and creatures apply primarily to God and secondarily to creatures (Davies, 1993). Goodness would not exist if it were not for God, who is Goodness. Though we draw language from creatures and the material world in order to speak of God, it is from God that creatures and the material world exist and have qualities at all. Insofar as creatures are perfect, they resemble God, even while God’s nature and perfections far transcend them. Whatever is said of God and creature is said in light of the causal order. God embodies perfections as their Maker, not as a mere creature.

To say, “God is good,” is not so say that God has the property of goodness, as though goodness were a thing that existed apart from God. Nor does it say simply that, “God is the cause of goodness,” for it would then follow that God were only good in a secondary sense. But surely, God would be good even if He caused nothing. Neither, Aquinas would argue, is it to say the negative – that, “God is not evil.” Such causal or negative interpretations, as held by philosophers such as Maimonides, are reductive and discount the intentions of the speaker. Rather, to say that God is good is to say something true and positive about God’s essence. By saying, “God is good,” one means that, “Whatever good we attribute to creatures, pre-exists in God, and in a more excellent and higher way.” Or rather, that God is goodness, because He is simple. Additionally, because the essence of God cannot be known by man, man cannot comprehend what, “God is good,” means with any great clarity – however, it is still a true and meaningful statement. “Good” truly describes God, though it is inadequate, in a similar sense to saying that Mozart is “musical” (Davies, 1993).

Aquinas stresses that, “God is good,” and, “God is goodness,” should both be said. Saying only the latter might risk developing the belief that God is abstract, while saying only the former might risk developing the belief that God’s goodness is like that of man. It must be stressed that this is not to use such terms equivocally of God and creature. “Good” does not take on an entirely different meaning depending upon its application to God or creature, and this is sufficient for man to know something of God’s transcendent goodness, even if to a limited degree. Statements such as, “God is good,” and, “This is a good coffee,” are literally true and demonstrate an analogical use of “good.” Positive, literal statements can be made of God, although they fail to capture His essence. Gregory Rocca phrases it well when he says, “Thomas's positive theology is rather like a blind person pointing to and making true judgments about a reality which he or she cannot actually see” (1993).

Considering all this, one can observe that Aquinas means argue that man can know God through causal order, negative theology, and excellence (or positive theology). Man can know that God is good because He is the cause of creaturely goodness. Additionally, God is not good in the same way that man is, because His goodness is far higher. Aquinas strives to strike a difficult balance between negative and positive theology, for while the former denies that man can know God’s nature, the latter asserts that man can make true judgements about God’s nature. He supports the general ideas of via remotionis, however, he refuses to allow statements about God to be reduced to a negative interpretation.

Herbert McCabe accurately summarises that, for Aquinas, “when we speak of God we do not know what we are talking about. We are simply taking language from the familiar context in which we understand it and using it to point beyond what we understand into the mystery that surrounds us and sustains the world we do partially understand.” Drawn from the natural world, The Five Ways, particularly the Argument from Efficient Causes, forms the baseline for Aquinas’ negative and positive theology. While we can ascribe true attributes to God, we have no conception of what these attributes are like as they exist in Him, for God is simple and above human understanding. Positive statements regarding God are validated by argument and acknowledgement of the relationship between cause and effect. Near the end of his life, Aquinas ceased to write, considering all his words as mere straw in light of the transcendence of God. At the core of the matter, man cannot know God’s essence and language cannot capture Him – however, this does not make our affirmations less true.

[1] This sets Aquinas’ view apart from “double-truth theory.”

[2] The idea that words used of God and creatures mean the same thing.

[3] The idea that words used of God and creatures mean entirely different things.

Aquinas, Saint Thomas. The Summa Theologica: Complete Edition. Catholic Way Publishing, 2014.

Brent, James. “Natural Theology.” Internet Encyclopedia of Philosophy. https://iep.utm.edu/theo-nat/

Brown, Christopher M. “Thomas Aquinas (1224/6-1274).” Internet Encyclopedia of Philosophy. https://iep.utm.edu/aquinas/

Davies, Brian. “Aquinas on What God is Not.” Revue Internationale de Philosophie (1998): 207-225.

Davies, Brian. “What God Is Not.” In The Thought of Thomas Aquinas. Oxford: Oxford University Press, 1993. Oxford Scholarship Online, 2003. doi: 10.1093/0198267533.003.0003.

Davies, Brian. “Talking About God.” In The Thought of Thomas Aquinas. Oxford: Oxford University Press, 1993. Oxford Scholarship Online, 2003. doi: 10.1093/0198267533.003.0004.

Floyd, Shawn. “Aquinas: Philosophical Theology.” Internet Encyclopedia of Philosophy. https://iep.utm.edu/aq-ph-th/

Rocca, Gregory P. “Aquinas on God-talk: Hovering over the Abyss.” Theological Studies 54, no. 4 (1993): 641-661.