The Existence of God - St. Thomas Aquinas and Fr. Gregory Pine O.P.

The Existence of God - The Brain in a Vat Argument

This argument is taken from the Catholic Answers website with the opening statement taken from a debate hosted by Pints with Aquinas where Fr. Gregory Pine O.P. debated atheist Ben Watkins. I will be summarizing Fr. Gregory Pine’s opening statement and remarks, then laying out the Brain in a Vat argument. All credit goes to him and James Kidd. 



Opening Statement - Fr. Gregory Pine O.P.


(Source: https://youtu.be/0QMwHUijmqo?t=270)

The proper Catholic teaching is that the existence of God is something available to natural reason. So it is classed among what is called the praeambula fidei, which would be the preambles of the faith. These would be the kinds of things that are, on one hand, discoverable by reason, but on the other hand are also revealed. There is a kind of overlap. That is the case because they are accessible, but also because to get there can sometimes be difficult, time consuming, or fraught with errors. But, God in His generosity sees fit to reveal those things so that none would be left without access by virtue of his overabundant generosity and revelation.



Sometimes we expect the proofs as they are so stated to be immediately convincing; we think about a geometry proof which kind of gives you this eureka insight it dawns upon your mind and it impresses its rationality. Whereas this is not commonly in the experience when one encounters the five ways of St. Thomas Aquinas. Typically one thinks them boring, arcane, overly complicated, and silly. So, you might think that this would militate against God's goodness. If so much rides on God making himself known, shouldn't He have it be more obvious that we come to Him? 

 Now what are some difficulties in attaining to such belief or in accessing this by reason? Well, there's simply the limitations of human nature for one. Mind you the revelation is addressed to us as humans but we need to be cognizant at the outset that we can only know so many things in so many ways; that we are limited by virtue of the fact that we are embodied souls born at a particular time and place and subject to all of the constraints in which we find ourselves. Within the Christian tradition we also talk about the difficulties introduced by sin, both original and personal. So our minds are darkened by ignorance, our wills are twisted by malice, and our passions are inflamed with concupiscence and undermined by weakness.


Add to this the fact of one's own personal formation. One may have taken steps down particular roads which preclude the knowledge of God because God might be seen in those settings as a forbidder of chosen liberties. And beyond personal formation there's also the fact of societal or cultural formation. So I would say that now is not an especially conducive time to belief because it's often construed as something backward, obscurantist, naive, and dumb. 


So then, how is one to counter said obstacles and how is one to attain to the faith which Christians seem to laud as so very excellent? Here, for our own purposes within the context of a debate founded on reason, we're trying to assume a particular point of view (at the very least). Namely, the view which St. Thomas adopts in his description of creation, what some call the metaphysics of creation. Here we can think about St. Thomas’ revelation of esse, the act of being.



The fact that everything that is, is in a particular way. It's in this way or in that way, but we need to account for the fact that it is as it is or, more basically or fundamentally, that it is at all. This isn't to tell a genealogical story or to say that we have to come up with some scientific master theory whereby to account for the progressive evolution of things so that they arrive at the present point. Because we are not so much concerned with development and dialectic as we are with a vertical vision. Vertical here does not need necessarily to import religious thought or thinking, but to say that when we encounter things in the world we see them as somehow dependent. We see them as somehow given and that language of dependence or givenness should cause us to wonder, which is the beginning of philosophy.



So in this third and final piece, let's turn to The Five Ways, the type of reasoning that St. Thomas espouses at the beginning of the Summa Theologiae. His first question is about methodology, his second question is proving that God exists (because he's a good Aristotelian scientist and you can't talk about what a thing is until you have grounded that it is), and so he gives these five ways of these five proofs. It should be noted that, in the 21st century, some work better than others. That’s not to say that they don't work, are bad arguments, or need be refuted, but it is to say that some are more appealing to a modern mind and some seem less so.


So we will focus on the first three ways, but to take them as a set of arguments. Not necessarily to take them each individually and go through the steps, but rather to think about what they're generally trying to show. These taken together are typically called cosmological arguments; they observe something about reality. Whether motion, efficient causality, or the fact there are contingent things. Each observes a similar approach, namely that there's some feature of reality and when we begin to reason back from it as an effect to certain causes, which account adequately or necessarily for it, then we come to some bedrock. It isn't to say that we looked for a first point in an accidentally subordinated series of causes. We’re not looking to go back until we find a first, we're looking to evaluate these things in reality and account for the fact that they obtain. We're looking to account for the fact that they are intelligible, that they are addressed to human minds, and that human minds are capable of accessing and penetrating such realities, engaging with them in such a way as to make sense of life. 

 One of the most basic distinctions that's at work in all of these arguments is that of act and potency. Act is what a thing is and potency is what a thing potentially could be, provided that it gets sufficient impetus to realize itself in said way. Basically what all of these different things observe is that we observe all of these causal chains of act and potency and we find that certain things go from what could be to what is. We also recognize the fact that they can't pull themselves up by their own metaphysical bootstraps, and so we need to appeal to something which can make sense of all of these relationships, make sense of all of these mutual entailed networks of causes, and provide for them a space in which it all obtains.



This for us is something that we do on an ordinary and everyday basis. It’s not just for professional philosophers. When something happens, for example on your way to work, you look for an explanation as to why. It's why we look at car accidents, we want to get some sense based on the damage dealt to both vehicles. That way we can have some adequate reason for our having been delayed. This is something that we just do; we seek a sufficient and necessary explanatory principle.

So, we need to account for the fact of things being or of things being this way and ultimately we get to the question, or some 20th century philosophers get to the question, of why there is something rather than nothing. A lot of Thomists would kind of take umbrage at putting the third way in such crass terms, but it has an apologetic appeal because at the end of each of these arguments St. Thomas is modest in saying that “this we call God”. He doesn't say that we've proved God, explained God away, or cast sufficient light on the mystery which is at the heart of God. He just says we have gestured towards something which begins to fit the description and, provided you permit me to take you by the hand, I will walk you pedagogically through a bunch of subsequent arguments about simplicity, perfection, goodness, infinity, eternity, omnipresence, etc. So we can fill out the picture which comports with that that is revealed, but ultimately the reason for which one believes is that it is revealed and yet our minds as given by God are capable of attaining to the truth as it is exposited and as it is explained.



Having proved the existence of God may not be the reason for which many claim there to be a God. One might hold to it for reasons of belief, suspicion, or opinion, just hedging his bets so that if there is a God things don't end poorly after this life. But, ultimately all we mean to say, and it's a modest claim, is that it is knowable as a necessary explanation for the very coherence and intelligibility of reality and apart from it things don't hang together as they ought and as they do.





The Brain in a Vat Argument - Inspired by St. Thomas Aquinas, summarized by James Kidd

(Source: https://www.catholic.com/magazine/print-edition/a-proof-of-the-existence-of-god)



Let’s start by taking a position of radical doubt. Suppose for a moment that you are not really a human being with an actual body. In reality, you are nothing more than a brain floating in a vat of fluids, with electrodes attached to various parts of your exterior that allow evil scientists to manipulate you into thinking that what you perceive is actually there, when in fact it is nothing more than an imaginary world constructed by the scientists.

Right now, they are making you think that you are reading this article when in fact you are not. 

From this point of extreme skepticism, we will prove beyond all possible doubt that God exists.



P1. One cannot deny one’s own existence.



Cogito, ergo sum. Even if you’re just a brain in a vat, your own existence can be verified simply by the fact that you perceive—that is, you see, hear, smell, taste and touch things. Whether or not your perceptions are accurate is another question, but even if you doubt your own existence, you must exist, for it is impossible for a non-existent thing to doubt. In fact, the very act of doubting proves that you exist. Therefore, denying your own existence is a contradiction in terms. I can deny yours and you can deny mine, but I can’t doubt mine, nor can you doubt yours. 



P2. There is at least one thing that exists.



It is possible for you to be deceived in your perception. In fact, it’s conceivable that every one of your perceptions is a delusion. But even if that is the case—even if nothing you think exists actually exists—you still must exist. Entity is the word we have for anything that exists. You exist, so you are an entity. 



P3. There is such a thing as existence.

You can know with certainty that there is at least one entity, at least one thing of which the term existence can be predicated. If there were no such thing as existence, nothing would exist, not even you. But, as we have seen already, that is impossible. As Aquinas would say, there must be an “act of being” in which all entities participate. This act of being must itself exist; it must be an entity. Thomas calls this entity esse, which is Latin for “to be” or “to exist.” 



P4. The nature of esse is actuality. 


Now that we have established that esse is an entity, we must ask: What is the nature of this entity? What is its definition? To answer these questions, we must consider existence by itself, apart from everything else.



What do we mean when we say that something exists? We mean that it is actual. For example, an acorn is actually an acorn and potentially a tree. A tree is actually a tree and potentially lumber. Lumber is actually lumber and potentially a desk. A desk is actually a desk and potentially firewood. Firewood is actually firewood and potentially ashes.

In other words, a thing is actually what it is right now; it is potentially what it might be in the future. Now when we say that something exists, we normally refer to actuality rather than potentiality. For instance, if I held up an egg and said, “This egg exists,” you would understand me, because what I am saying is “This egg is actual” or “This is actually an egg.” But if I held up the egg and said, “This chicken exists,” that would not make sense to you, because even though the egg is potentially a chicken (that is, the chicken exists potentially), the concept of existence applies primarily to the egg’s actual state and only secondarily to its potential state.

Now potentiality is still a form of existence, but we realize that it is, in some sense, inferior to actuality. In other words, potentiality is a “shade” of existence the same way that pink is a shade of red. Just as we would say that pink lemonade is red but not in the same way that Hawaiian punch is red, so we say that potentiality exists but not as much as actuality does. Actuality is the fullness of existence. So, again, taking the brain-in-a-vat hypothesis, you know that you are actual, even if nothing else you perceive exists. 



P5. Esse is nothing but pure actuality.



Potentiality is a privation of actuality. That is, it is not a thing in itself but the absence of something. In the same way, darkness is not a substance itself but the absence (or privation) of light.

Now a thing considered in itself contains nothing but its fullness. The nature (or essence) of light consists of nothing but light itself; it does not contain darkness. Therefore, the essence of esse contains nothing but its fullness, actuality. There is no potentiality in the nature of esse. Thus, the essence of esse is pure actuality, just as the essence of light is pure light.

Thomas argues that all entities participate in esse insofar as they are actual. Therefore, that in which they participate—esse—must be actual. In fact, it cannot admit of any potentiality. 



P6. Esse not only does exist but must exist. 



Existence itself is pure actuality, with no potentiality in it. This means that the essence of existence is nothing other than existence. Existence is its own essence. From this it follows that esse itself must exist, for if it did not, it would violate its own essence, which is impossible. 



P7. Esse is distinct from everything else that exists.



You can know from step 1 that you exist, and we know from step 3 that esse exists. But we also know that the two are not identical. 

Let’s say you’re just a brain in a vat, that everything you perceive is an illusion. You can still recognize that, while you are actual in some ways, you are potential in other ways. You actually perceive that you’re reading this article right now; you’re potentially perceiving something else. You are actually existing right now; you potentially exist five minutes from now. Moreover, anything else that may exist has the same attribute: Its essence is composed of both actuality and potentiality. 

 But, as we saw in step 5, esse is nothing but pure actuality. Thus, it must be distinct from any other entity. 




P8. Esse must be one.



If there were more than one esse, then there would be distinctions among them. But distinctions imply limitations, and limitations imply potentiality. But since esse is pure actuality, it has no limitations, which means there is no distinction in esse. Therefore, there is only one esse. 

P9. Esse must be immutable. 

 Change involves potentiality. In order for something to change, it must first have the potential to change; it must have a potentiality that is to be actualized. But since esse is purely actual, it has no potential to change. Therefore, esse is unchanging. 



P10. Esse must be eternal.

Time is nothing but the passing of the future into the present into the past. It is the changing of the not-yet into the now into the no-longer. But because esse does not change, it does not change from the future to the present to the past. It must be outside the realm of time, which means that there is no future, present, or past with esse. In other words, esse is non-temporal, or eternal. 



P11. Esse must be infinite.



Space is nothing but the changing of the over-here to the over-there. Anything that is actually here is potentially there. But because esse is immutable, it must be outside the realm of space. It has no spatial constraints—that is, esse is infinite. 



P12. Esse must be omniscient.



Even if you’re a brain in a vat, you can perceive that you have the capacity to know. Because you are only partly actual, and esse is purely actual, esse must know all there is to know. That is, esse is all-knowing, or omniscient. 



P13. Esse must be omnipotent.



You can perceive that you have the capacity to do some things that are logically possible. Since you are only partly actual, and esse is purely actual, esse must be able to do all things that are logically possible. That is, esse is all-powerful, or omnipotent.

In Conclusion



We have thus proven the existence of a being (esse) that not only does exist but must exist and is one, unchanging, eternal, infinite, omniscient, and omnipotent. This matches our definition of God that we stated at the beginning.



We can conclude, then, that even if all of your sense perceptions are false, even if you are nothing but a brain in a vat being manipulated by scientists into believing that you are reading this article right now when in fact you are not, there are two things you can know with absolute, 100 percent certainty: (1) You exist, and (2) God exists.