In this post I will give a rundown of one of the most central and oldest arguments of natural theology, with roots all the way to Aristotle, The First Way of Thomas Aquinas, or the argument from motion. Here is the argument in its most common form:
The project of Natural Theology is by no supposition a new one, with roots in ancient Greek philosophy, and this argument is of no exception to being quite aged. Originating as a staple of Aristotle’s causal order, with Him being both the Actus Purus and serving as the worlds final cause, the Unmoved First Mover has gained a wide array of recognition, perhaps being the most iconic piece of Natural Theology in existence. Aquinas in particular refined this argument to it’s fullest conclusion, and successfully moved the act potency distinction within Christian Theology. Problems related to Divine Causality, Free will, grace, and various others have all been explained by using this formula. The distinction itself arises due to our cognition of change. For although this is a universal distinction describing all of reality, we come first to know of the distinction through our senses, seeing the subjective potencies and accidents gained by the objects of our experience, and then moving beyond them (which we will discuss later). Our knowledge of essences starts from the objective dispositions of them placed upon our intellect, and the fundamental ways in which they work, and from this we can tell whether it existence is non accidental to them. For Aquinas argues that even the essence and existence paradigm is a variety of the Act Potency one, with an essence being in potency to an act of existence. With this background in mind, we will move forward with the proof:
- Our senses prove that some things are in motion.
- Things move when potential motion becomes actual motion.
- Only an actual motion can convert a potential motion into an actual motion.
- Nothing can be at once in both actuality and potentiality in the same respect (i.e., if both actual and potential, it is actual in one respect and potential in another).
- Therefore nothing can move itself.
- Therefore each thing in motion is moved by something else.
- The sequence of motion cannot extend ad infinitum.
- Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.
This argument uses plenty of metaphysical terms and hence, a introductory guide is quite useful as a companion help the reader. To word it simply, we observe change, which is what motion means in a scholastic sense. Actual motion is causal perfection or causal prowess. In the fullest sense it is the presence of a perfection that completes a particular object. In the case of someone learning German, the German teacher would be actual as far as the breadth of knowledge on the subject goes, having learned German (I would hope). A pupil in the German class would have merely the potential to learn the language, but as of yet, this ability has not been actualized. For something to be potential is for it to be a objective disposition or a perfection to be gained by an object. Now the reason this distinction is of necessity is best displayed by the various absurd positions held before this distinction. For example Heraclitus, the greek philosopher held that all of reality was in flux without any real objective stability. The objection immediately raised against Heraclitus was how could such a principle not break the Law of Contradiction, since under this philosophers formula something both is being and becoming in the same respect. Heraclitus’s answer was to deny the Law of Contradiction held for anything more than dialectical dealings. In order to deal with this (although he was more directly dealing with the next philosopher), Plato bit the bullet, and yet said that we do have knowledge based on our experiences with the Realm of Forms, that we can recognize some objective resemblance of the things we see in fleeting moments, due to us recognizing the forms in which they exemplify. This is because the forms are unchanging and immutable, antithetical to the reality of our experience. Taking the opposite extreme was Parmenides who held that all of reality was one and distinct. The reason he held such an extreme position was under the assumption that being was the only thing that could exist. For change in reality can only emerge from one of two things, being or non being. But from nothing nothing comes. Hence, only being can produce the reality we see. This seems all well and good until we see Heraclitus’s conclusion. For he reasons that something already in being is already in being, and hence no change would have occurred. Secondly, since everything is being, the only way to distinguish two objects would either be being or non being. If it is non being, then how can the absence of being explain a difference? However, if it is being, then we run into an issue we ran into with change. For how could one distinguish based off existence, which is common to all beings? Parmenides thought you could not, and hence all of reality was one and unchanging, a sort of block.
Aristotle argues that the all of these views are simply mistaken. Heraclitus, trying to argue his position actually commits several obvious fallacies. For to present this argument to an interlocutor, one would have to consult a variety of premises, and consult them in such a way that assumes stability. For if all of reality is in flux, one could not in principle present such a conclusion. One can simply retort that his “proof” is self referentially incoherent, that there has to be a distinction between being and becoming. Secondly, since we work in the order of knowing, and since being is prior to knowing, any conceptual principle would have to be prior to the act of judging. Now the Principle of Non Contradiction is such a principle. Therefore, it follows, that the Principle of Non Contradiction does not merely govern the conceptual realm, but also any coherent ontology. How can one assume that ones intellectual judgements are protected by the law, when not arguing for it’s applying to reality? Therefore, it follows reality has some stability, even if change does occur. After this Aristotle argues against Plato’s solution to this problem. It can even be questioned whether Plato’s solution solves the problem, as he cannot consult his intellect which is again in the unstable world of Heraclitus (Plato’s matter based solution is interesting, but we will not consult it right now). Aristotles main argument is due to the gratuitousness of the forms, and the data of our experience. One does not need to posit a realm of forms when the forms can merely inhibit the particular substances of our existence. For the intellect, when judging something comes across the forms not in a previous life, but by abstracting the particular tendencies of a subject and it’s final cause. It removes any of the principles of limit that obviously exist in this life, and abstracts them towards the final universal concept. In spite of this, the form is not merely an abstract sort of thing, but something that actually serves almost as a nature to the particular subject. It both grounds the type of thing any particular being is, and also the unique potencies it has. It provides a sufficient explanation for why an object has t dispositions and powers another one does not, and has limited cost on any ontological economy. Now one might ask why the form is limited in reality, since the sort of things Plato talked about were perfect. Also, what happens when a particular change occurs that is not related to the form gaining a property, say when a dog biodegrades into the dirt? Aristotle posited something called Prime Matter to do the work here. For Prime Matter, which is in potency to any form (that is it is literally infinite potentiality) both limits a item in space (where it is located), and also the degree of perfection it has in reality. Secondly, in the midst of a change of substance, something has to serve as the substratum of change. For when something changes, experience dictates that it is not merely annihilated and recreated. For there is a real layer that stays. When we see something melting, there is a really similar feature about the new object formed, even if it is not completely the same. The form is absent, while a part of the being continues on. Only a framework that can match both of these experiences is to be preferred. Hylomorphism (the thesis that all material objects are composed of Form and Prime matter) according to Aristotle is the only the only option of preference. Both of these distinct parts constituted what is called a substance, which Aristotle posited is anything with causal powers in any sense part of our experience.
Now that we formed a frame work we can move to the objections of Parmenides. Firstly, Aristotle argues change is such an obvious feature of reality that a denial of this should not be taken extraordinarily seriously. Parmenides is undergoing a change in his mind when he delights in the argument (even if only introspectively) and when he presents it to an interlocutor. How can one deny this? A theory is absurd that denies explicitly what it affirms implicitly, and Parmenides no change thesis is an obvious example of this. Secondly, how can Parmenides hold that only one thing exists? For when one peers inside oneself, she experiences herself as a unified whole, with all of her causal powers being experienced in this way as well. As Berkley argued, when one raises her arm, she manifests causal powers that are so real and obvious that a denial of this seems all the worse off. You are however, separate from the world outside you, and this is again obvious from your introspective experiences. However, we can perhaps even represent the first argument against Parmenides full circle to show this point. If all of reality was one and undivided, how could he present such a proof without consulting distinct premises in a syllogism, while also taking objections from an interlocutor? The same argument against the first premise can be presented here, and hence his position is reduced to absurdity.
Parmenides presented a distinct proof for his position related to being we will address here. This point is especially relevant to the prospects of natural theology. For the fallacy is hidden implicitly but is able to be bitten when one truly sees it’s obviousness. For Parmenides is using being in a univocal fashion, when it is very plausible it is not. To be univocal a term needs to be used in the same way across beings. Typically these usages are few and far between, as they rarely even apply to the same genus. An example of this would be the words “run” in both dogs and man, which share the same basic meaning. The opposite extreme is equivocation, which is when two objects, while predicated using the same word, are predicated in a entirely different order. An example of this is when you call a doctor a quack, and also say that the duck made the noise “quack”. These are manifestly not representing the same reality, even if the word is. Now the middle ground Aristotle took was to note that being is an analogical term, which is to say it is predicated both similarly and differently of two particular subjects. An example of this would be “The Sun is smiling at me” and “Brenda smiled at me”. This, an analogy of proportion, is constituted both by a clear difference, while also being similar in a very important respect. There is something really alike in the two beings. Aristotle argues from this truism that being is a term of this sort. For if it were not, we would run into the sorts of problems Parmenides spoke of. While a thinker like Scotus had the tools to speak using a bare univocal definition of being, Parmenides did not. More importantly however, it actually seems true to say that things exist in different ways while still both having some resemblance in their status. For it is obvious while a horse doesn’t exist in the same way that a quark does, there still is some obvious likeness. So Aristotle’s position receives vindication.
With this in mind, we can present the Act-Potency distinction once more. Aristotle, due to these issues just posited, divided being into two distinct categories, being in act and being in potency. As we have said earlier, being in act is the fullness of a particular perfection, possessing a particular attribute one was merely in potency to. Being in potency is related to being as act as the disposition for a particular perfection. An obvious example for this would be a subatomic particle. A sub atomic particle, by definition is located at a particular point in space, say point A. It is in potency however, to the perfection of being in point B. If say such a particle were moved, something would actualize the perfection that was once merely in potency. Now local changes are not the only possible changes one can have. For one can grow in knowledge (which is not obviously local), one can change a color when mad, one can grow bigger etc. Qualities, Quantities, local changes, and substantial changes are all incorporated to Aristotle’s Causal thesis. It is important to contrast this with the change we discuss earlier that allowed us to posit Prime Matter. This is what Aristotle called an accidental change, one not essential to the being. Accidents are not the sort of things that exist in and of themselves, but exist by resting in a substance. Aristotle also reasons from applying the Law of Contradiction to this problem that a being cannot move itself. For a being to actualize a potential in the same time and respect, by itself and from itself, is for it to both possess and not possess a particular perfection, which is absurd. One can perhaps argue that we have an obvious counter example to this in the actions of free creatures (Aristotle even thinks rational creatures are by definition self movers and most Scholastics felt creatures did move themselves with regard to their free will). Now the solution to this apparent difficulty is found in the contents of such movements. When a creature move’s itself, it is only on the basis that one part moves in relation to another, forming a particular action or deliberation. This is not self movement in the fullest sense, and hence is not a real counter examples. There are some interesting tidbits about the contents of this discussion (for the record Suarez was probably right), but that is neither here nor now. Another counter example posited is that of inertia, since this thesis seeks to show object’s in motion tend to stay in motion unless acted upon by another. This is obviously not the only type of change discussed, but it is of a particularly great variety in our daily experience. Now there are various way’s one could argue against this, but there are three solutions of notoriety. Firstly, one can adopt the stance that Newton’s theory implicitly assumes such a distinction as act and potency. For since rest is the absence of motion in Newtonian physics, motion is merely a state actualized, with no need for any continued actualization. While this seems plausible, this faces a number of difficulties A. (Are spatial relations not things that need to be actualized, things that cannot be done by the object in itself?) and B. (Would not such a position seem quite absurd to Aristotle’s model?). These two difficulties seem insurmountable with regards to the problem. Secondly, one could adopt a sort of impetus theory, and say that the object which creates the motion in a particular agent allows the body to tend towards it’s place because of an “imparted form”. Thomist’s like Lagrange argue this to be viable, and there is a historical case to be made that Aquinas held this view too. The obvious issue with this however is that many, if not most of the forms imparted are finite, and inertia is infinite (at least with regards to movement). However, the defender of the impetus theory could charge the inertia proponent with an absurd position, for how can the fact that this effect be continued forever be explained by a finite cause? The impetus theorist, placing metaphysics at a higher place than physics sees the Newtonian’s assumption as not remotely justifiable. Newton’s laws are based on a few generalized test, and the impetus theorist would say that her model both explains the data while preserving a legitimate metaphysical assumption, that a being cannot give more than it has, which is the case of the cause who both stops (and if need be) and starts the motion. The Impetus theorist has a plausible stopping point here. It even becomes more viable if one assumes that the impetus provides a potentially infinite amount of power, although this supposition seems quite strange and unhelpful. The most popular solution to the problem is to posit a sustaining cause, even in the face of it’s counter intuitiveness. The reason is a sustaining cause can both carry the motion forward in a potentially infinite regard, and is empirically equivalent to the inertial motion theorist’s results. For since this is under a generalized condition, perhaps when one comes into a potential stopper (like say an object in the way of a projectile), they can posit the cause simply bracing for impact (in an analogical way of course). This seems to work, but the question is why one should one posit this cause at all? It is obviously simpler to ontological economy to go without it. However, since a First Mover bears a great deal of benefits with regards to other forms of motion, this device is already in the Thomist’s ontology. More importantly, is not obviously antithetical to all of Newtonian physics either. To note a physical example in which a sustaining cause is still needed, one need not look further than multi directional uniform motion. As GH Joyce states: “Motion which is of two or of three dimensions may also be uniform. Thus we have uniform motion of two dimensions when the movement of a body round a point is such that equal areas are swept by the radius vector in equal times. No one questions that uniform motion of two dimensions demands an external agency for its realization. It seems difficult to explain why, if a regulating cause is requisite in the one case, it is not equally necessary in the other. Again: we are familiar with the phenomenon of uniform acceleration with regard to time. The motion of a falling body increases in arithmetical progression. Here, too, we postulate an external cause, without which the acceleration is declared to be inexplicable. But it may be questioned whether uniformity of velocity is really a whit more intelligible apart from the efficiency of an agent actually present than is uniformity of acceleration”. If a sustaining cause is needed in this physical example, why not hold one in other conditions? Obviously the cases are different, but it shows that such devices are not utterly repugnant to modern physics. The three options show there is serious wiggle room for the Thomist, and that there are incentives to hold the respective positions. The first position, while deemed deficient, does preserve the Newtonian formula in it’s complete glory. The impetus theory might preserve the traditional Thomistic view, while contradicting the results of modern physics, and yet provides justification for doing so. It is however deemed by the writer that the sustaining cause thesis both is the least absurd and explains away the results of modern physics in a clear way. If one places being as being, the study of Metaphysics, above physical theories, one can see the incentive to accept such a formula, even facing the weight of modern physics. One is not arguing with the results per se, but merely the interpretation.
With this background in mind, we will now proceed to the argument. The first premise was already pressed in the reply to Parmenides. For almost nothing is more evident in life than the fact that change occurs at least introspectively. How can one with any seriousness deny this? It is manifest that any argument against motion is far less obvious than the thesis that motion exists, and that any argument against change relies on motion as well. The second premise is a reformulation of the act potency paradigm. We have just proved it’s usefulness previously, and it seems to be the only thesis that accounts for the robust change among stability we observe in the world. The third through fifth premises are perhaps a bit controversial, but it relies on the Law of Contradiction applied to the world of being. For if something actual was not actualizing the potential of another, then what is truly doing the actualizing? It cannot be the thing itself, for as we have shown, this would break the law of non contradiction. Nor can it be nothing, because from nothing nothing comes. Modern Quantum physics has not shown this supposition to be in flux, for the indeterminacy of a vacuum does not denote that there is not cause. We will go into arguments from the Principle of Sufficient Reason later, but this provides excellent justification that the Principle of Causality is a necessary explanation for things that come into being or are sustained in being. Aquinas felt that the First Mover moved our wills indeterminately, and hence, he already had a mechanism in his ontology capable of moving non mechanistically. The Philosophy of Nature adopted by Aquinas and Aristotle was not merely mechanic in essence, but purpose filled, and almost any perfection could be instilled to a secondary mover as long as it is within reason. It also had to befit the nature of the instrument.
Premise seven is often confused as an argument against the existence of an actual infinite, which is not actually the case at all. Aquinas had no noticeable issues with the existence of an actual infinite in comparison to a writer like Craig. He did not think the universe could be demonstrated to have a beginning, and hence none of his arguments require that (although the third way pushes for that being a very reasonable situation). Aquinas did actually have experience with the series spoken about by Craig, even if most were in the form of a traversal argument. What Aquinas was arguing against were what is called essentially ordered series, like a hand moving a stick, moving a rock, which in turn moves a leaf. This is the example Aristotle gives, in which if a potency withers away, the series terminates. Each mover is working roughly simultaneously, and hence there is no room in between for a mover to cease operation. He did not have issues with say, a continuous string of parents having kids, where when the parents died, their children still could function adequately in the future without them (The second way goes into this more). This is what is deemed an accidentally ordered series, and is the thesis someone like Craig accepts as absurd with regards to actual infinitude. In Aquinas’s mind if a finite amount of movers could not in fact give a sufficient explanation for the motion in a series order per se (An essentially ordered one), extending it to infinity has not suddenly created one. Even if an infinite regress could occur, something would be needed to impart their causal powers and perfections, something not within the series itself. Lagrange gives his argument in the form of a broom stick. Like a broom, a series of causes merely in potency to a particular perfection are deficient with regards to fulfilling their end, as a broom is with regards to sweeping without an agent moving it. The broom is manifestly finite, and yet moving it’s handle to an infinite length will not allow it to impart motion by it’s own doing. In the same way, a series that is merely in potency to act will not be given the power of movement even if such a series is infinite. Now one might object that such a series is quite odd. For modern science has shown absolute simultaneity to be a patent fallacy. Granting this even if not necessarily the case, the series we are discussing is not based on a temporal argument, but one about explanations. Just as a block painting can have a certain hierarchy within the frame it fills, so can causes such as this. This argument is not strictly temporal, with these causes operating in such a way that modern physics does not touch it. Still, one can even challenge the notion that these movers are not functioning in an event based order. Movers move in relativity to another event, and yet we would just argue the events are separate. For it is our very argument that the series just discussed is an event based series, constituting a single event, no matter how many movers are involved. Hence such a trouble evaporates. Another challenge to simultaneous causation is whether it is possible for a simultaneous series to not be instantaneous, with the event just ending immediately. This is a robust challenge, and yet one answered by the Metaphysicians Rani Anjum and Stephen Mumford. The reason simultaneous causation is not a chimera is because the sort of series is simultaneous over an event, which takes place in time. An example of this would be a ice cube melted by the sun. The melting of an ice cube is caused simultaneously by the sun beam’s thermal powers, and yet it is not instantaneously melted, because the total cause happened in a temporal sequence. This shows such a rebuttal is wrong headed, only indirectly facing an argument like this. When the hand moves the stick, he does so not once instantaneously, but over a sequence lasting as long as the series continues. With these rebuttals out of the way, we can arrive at a being who is Pure Act, not the sort of thing that could in principle be set in motion, and oneat the top of the causal hierarchy.
Now a couple arguments about the conclusion can be set up right away. Why should one conclude the First Mover is immutable, and cannot be set in motion by anything else? Could it not be a brute fact that a part simply had this perfection and was able to terminate the series? Well upon looking at the total series such an argument becomes deficient in several respects. For one, either the mover actualized at the top of the chain had that perfection essentially, or it had to be moved to actualize this perfection by a distinct part. If the part is not the sort of being that can be moved towards such a series, it is pure act. If, however, the part only moved to participate in such a series because it was moved in relation to another part, it becomes manifest such a mover was actualized by another and hence part of these series. This makes it clear that the First Mover is not the sort of thing composed of parts, because if it were, then such a mover would have an Act in relation to the other parts that were previously in potency, requiring the First Mover to have been moved by another which is a patent absurdity. Nor can such a being gain accident’s, for accident’s are in potency to a substance which is in act. Hence, it follows the First Mover is entirely simple and immutable. Such a being could not pass into being in potency to being in act, and is hence eternal, essentially so. The school boys retort about “Who moved the First Mover?” is protected in this argument. Now an interlocutor can object that an immutable mover is a contradiction in terms, for how can one act without changing? We can give a few examples of such an event, as this is clearly not fallacious when one digs beneath the surface. When humans move after a particular sense appetite, they do so because they were moved by the particular goods of the item. The item never need be touched, but such an item did function as an unmoved mover to the agents who acted upon their appetitive tendencies. Another example of a unmoved mover would be a professor in a class, who could be presenting his knowledge for all eternity on a chalkboard (the in’s and outs of such an analogy are not important), allowing others to gain in knowledge while he does not in any real sense change in this respect. While not all of the First Mover’s movements will be by mere intellectual influencing, we do have some obvious analogies. The First Mover is eternally acting, while no change is going on within Him.
The most obvious issue that can be raised is from the definition of such a being, as an opponent can object that such a being is not necessarily God. Why does Aquinas end with the conclusion “and this all men call God”? We will touch on this in greater detail when we discuss the attributes of the Deity, yet we will mention some points here. To begin, all Aquinas meant by this line was that among what God is, He is also the First Mover set in motion by no other. Aquinas dedicates extensive proofs to the properties of the deity, and sort of expected his readers to follow up on those. We will in our short time mention some of the attributes we can derive. The First Mover will both contain intellect and will, because if He did not, then how could He move and concur with free intellectual agents? While the contents of this concurrence will not be discussed as of now, in a weak sense the First Mover must move along side Human agents, allowing them to realize their self induced ends. Some of the actions humans do is immanent (ie inside the agent), while other actions are transitive (outside the agent). The only beings capable of doing (even if God’s doing is simply weak concurrence) both of these actions are ones endowed with intellect and will. Therefore the First Mover is intellectual and willing. Secondly, this feature is assumed by the fact such a First Mover is a self Mover (in a weak sense due to His essense being fundamentally inclined “towards” movement, with the First Mover literally being an act), setting himself in motion “towards” the series. For the only beings capable of moving themselves in towards a good are those equipped with desire and apprehension (even if the beings in our experience only do it because of a continuous actualizing of parts). Now the First self moved mover cannot be so on account of any proximate good, for all proximate good’s are prior to the appetitive desire, while the First Mover is posterior to none. If He were posterior to a good He would be moved by a particular good non essentially, which is impossible and in explicit contradiction to the First Mover’s natural immutability as we have previously shewn. Nor can He do so on account of any parts that need actualizing, for as we have displayed the First Mover is not composed of parts. Therefore the First Mover has to move on account of His own goodness. Furthermore, this goodness will have to function as His beatitude. In a being not composed of parts however, what can limit the goodness of such an agent? Also, for something that is Pure Act, with all real perfections essentially, how can one not be perfect? Therefore, it follows the First Being is perfect as well, and only acts on account of His own goodness. Everything moved is on the supposition of the glory experienced within the First Mover’s beatitude, and His wish to spread His own goodness to the world. When humans deem something good, they do so on account of it’s desirability, and anything that is infinitely desirable and perfect is also infinitely good. It then follows the First Mover is unlimited goodness. Obviously this proof has already been shown with regards to the First Mover’s tendency, but it can be displayed as objective through the judgement of men’s experience. Furthermore, Given that God is pure act, and that no perfection is not found in Him on account of this, it follows God is utterly omnipotent. No movement or causal disposition is repugnant to the First Mover. This same proof can be used to argue that the First Mover is all knowing. Since the First Mover is a being endowed with intellect and will, it truly is open to all intellectual data. This means facts are something the First Being is in potency to. However, the First Mover can stand in potency to no things, but must contain all perfections essentially. It then follows that there is no knowledge that is not contained in a preeminent sense within the First Act. Next, it is manifestly clear the First Mover is not composed of matter and form, hence being immaterial. Anything material is composed of matter and form, ordered in such a way akin to potency and act. The form, being the determinant bearer of perfections is in act to Prime Matter, which both limits and forms the compound (since Prime Matter is potentially anything), which is in turn in potency to from. However, the First Mover can stand in potency to nothing, nor is composed of distinct parts. It then follows that the First Mover is not material. Secondly, anything material is in potency to division, as it is of a determinant length. However, the First Mover stands in no potency to anything and is hence not material. Thirdly, whatever is material is spatial, and is limited to a certain area. However, the First Mover stands in no potency to any specific spatial relation as he could neither be moved there nor move himself there, as no bodies are capable of such self movement in the sense just described, and the First Act is also unlimited as we have previously shewn. Therefore again, the First Mover is the First Act. Lastly and most magnificently, there can also only be one First Mover, as all movers have to be distinguished from each other by some part. However, the First being is not composed of parts. Therefore, it follows the First Being is essentially One and Unique. It is to be noted that all the perfections we have just proved are not found in a divided sense, but formally constituting the essence of the First Mover.
These arguments allow us to arrive at a being who is Intellectual, willing, Goodness itself, Perfection itself, simple, omnipotent, omniscient, immaterial and so forth. It is obvious why Aquinas felt this was “what all men call God”
Overall, I do think Aquinas’s first way still does work as a plausible argument from natural theology. Not based on the natural sciences like the arguments used by most apologists, it has unfortunately fallen out of favor. This is also largely due to the moderns disillusionment with a medieval argument. However, the explanatory power and the wide reach of the argument speaks for itself.