Author: Daniel Shields

At November’s American Catholic Philosophical Association conference in Houston there will be a panel discussion of my book, Nature and Nature’s God. Participating will be myself, Rob Koons, Alex Pruss, and Ed Houser. If you are attending the conference, please join us.

In my book I argue for a new, non-metaphysical interpretation of Aquinas’ first way and his other unmoved mover arguments. The arguments are natural philosophical ones. Understanding and defending the arguments require rolling up one’s sleeves and getting into issues of medieval cosmology and modern physics.

Until quite recently I have tended to use “concept” as a synonym for Aquinas’ terms “intelligible form” and “intelligible species” in the intellect. Aquinas does not use the Latin conceptus as a synonym for intelligible forms as far as I’m aware, but to students and non-experts in medieval philosophy “intelligible form” sounds too foreign. “Concept” seemed like an acceptable, familiar alternative.

But I have been reading Aquinas’ Treatise on the Trinity in the Summa and there he does use conceptus as a term, saying that “the mind’s interior concept/conceived thing (conceptus) is called a word (verbum).” (ST I, q. 34, a. 1, c. See also I, q. 27, a. 1.) As the Word of God, the Second Person of the Trinity originates from/is conceived by/is spoken interiorly by the Father. And a word/concept is distinguished from an intelligible species (I, q. 34, a. 1, ad 2.) An intelligible species is not posterior by nature to the act of understanding. But the concept/word is; it proceeds from the intellect. Hence a concept is to be distinguished from an intelligible form.

This distinction helps to solve a problem with Aquinas’ and Aristotle’s epistemology. Both of them hold that we come to understand something when the very same substantial form that exists in the natural substances of our experience comes to inform our intellect as well. It exists in the intellect not as a “natural form” but as an “intelligible form,” which has “intentional existence” rather than “natural existence.” The form of dog, for instance, takes on a new mode of existing when it informs our intellect; rather than making our intellect a dog, as the form does in its natural existence, it instead makes our intellect to know the essence of dog. Aquinas does not mean that there is a representative in our mind standing in for the essence of dog; rather the essence of dog itself is there, in an intentional mode of existence. Hence there is no problem in Aquinas’ theory of trying to bridge the gap between the mind and the external world by verifying how much the representation in our mind is like the dog-essence out there in Fido. This would be impossible since we would have no independent access to the essence out there to verify the similarity/lack of similarity in the representation. According to Aquinas, the form in our intellect is the very same form as that in Fido, Rex, Chester, and Rover, and so there can be no question of similarity/lack of it.

This understanding, if plausible, solves the “content fallacy” objection to Aquinas’ argument for the immateriality of the intellect. For it is not that the mind has something that represents an immaterial, universal essence. In that case, the content/thing represented could be immaterial while the representation and its subject (the intellect) could be material. Rather, to know the universal and hence immaterial essence, the mind must itself be informed by an immaterial, universal essence. And such an immaterial universal cannot exist in matter. Thus the intellect is itself immaterial. (The form of dog, say, is the form of particular material things, and hence exists in matter in its natural existence; but in its intentional existence it becomes immaterial and thus universal in its scope, no longer restricted to a particular instance of its kind.)

But Aquinas’ and Aristotle’s position here can seem implausible. For how can we say that we have the very same form in our intellect as exists in the world outside when we find that we can misapprehend the essences of things, and we need to revise and reconstruct our concepts of them? As a friend said to me recently, Aquinas thought that fire was an elemental body, and that turned out to be wrong. Surely Aquinas had enough experience of fire to possess the kind of phantasm from which the intelligible form of fire could be abstracted.

But here is where I think the distinction between an intelligible form and a concept becomes quite helpful. (I wish Aquinas himself brought what he said in his discussion of the Trinity about words/concepts into his epistemological texts. Perhaps he did somewhere and I’m not aware of it.) Our concepts are things that we construct; they originate from our intellect once it is informed by intelligible species. These concepts express to oneself, interiorly, what one knows. The concepts, not the intelligible species, are the things we are readily conscious of. Intelligible species are things by which we know the essences of physical things, but we do not have any ready cognitive access to the intelligible species themselves. On the other hand, the concepts we conceive in our minds are readily accessible to us.

But just as one can express oneself poorly to other people, so too the concepts one forms can express to oneself one’s intelligible forms poorly. We can misconstruct our concepts, and they can be in need of reconstruction. Most people, however, once they have formed their concepts, cannot think outside those concepts and have a hard time understanding other ways of looking at things. One of the things that philosophy is good at is teaching a person how to get behind his concepts and grasp other conceptual frameworks (think Kuhnian paradigm shifts; compare MacIntyre also.) Once one does this, one can then evaluate which conceptual framework more accurately captures reality. This involves comparison to one’s experience, but because sense-experience does not itself present essences or universals, to evaluate competing conceptual frameworks one needs more than a comparison to sense-experience. One must compare the conceptual frameworks in question to the intelligible forms that one has sub-consciously within one. Do the concepts one has been using accurately capture what one knows about reality? If not, what concepts might capture them better? Aquinas’ concept of fire was in need of revision, even if he possessed the intelligible form of fire in his intellect. Precisely because one has these intelligible forms in one’s intellect, the process of choosing between competing conceptual frameworks (e.g., Kantianism and Aristotelianism) is not a hopeless task. It is possible to see which set of purported concepts and principles is more true.

But unlike our concepts, the Word of God expresses God and His knowledge perfectly. The one Word eternally expresses God Himself and everything. Praised be the Blessed Trinity!

There is a second podcast about my book available, this one a quicker listen than the previous one. You can find it here:

https://wyomingcatholiccollege.podbean.com/e/nature-and-nature-s-god-with-dr-daniel-shields/

While you are at it, check out these other two podcasts, unrelated to the book:

A Philosopher reads St. Thomas:

https://wyomingcatholiccollege.podbean.com/e/a-philosopher-reads-st-thomas-aquinas-with-dr-daniel-shields/

Augustine’s Confessions:

https://wyomingcatholiccollege.podbean.com/e/augustine-s-confessions-with-dr-daniel-shields/

My book on Aquinas’ First Way was released this past Monday. It has been forthcoming for over two years, and some interesting contributions to the conversation have appeared between the time that the book was accepted for publication and the day it was finally published (such as Oberle’s article discussed in an earlier post.) In particular Joseph Schmid and Daniel Linford have written an interesting book Existential Inertia and Classical Theistic Proofs. Most of the book is not directly relevant to my interpretation of Aquinas’ proof, since I deny that the thesis of divine conservation has anything to do with Aquinas’ unmoved mover proof–unlike, say Edward Feser or Gaven Kerr. I believe in divine conservation, but cannot yet see how to prove it philosophically. (I have some hope that I will grasp the reason for it eventually; it took me 15 years to see why there must be a real distinction between essence and existence in mundane beings, but it is now clear to me.) In previous articles that I have read Schmid (and Oppy) raise reasonable and significant objections in favor of existential inertia.

The first chapter after the introduction of Schmid and Linford’s book is relevant as it deals more directly with the First Way, although they disavow any purely historical claims about Aquinas. They are trying to respond to contemporary Thomistic interpretations of the First Way. Schmid and Linford have raised a number of serious and reasonable objections to the First Way, objections very similar to ones I raised in my own book to the First Way as commonly interpreted.

Schmid and Linford argue that there is nothing in the logic of the First Way that rules out the possibility that different (essentially ordered) causal chains end with different first movers. Nor does the logic of the argument rule out the possibility that the unmoved mover that terminates any given causal chain is moved or movable in other respects irrelevant to its ability to initiate the causal chain in question. Finally, there is nothing in the logic of the argument that rules out the possibility that the unmoved mover terminating a given causal chain is unmoved in the relevant respect but yet not unmovable in that respect. The only thing that the logic of the argument shows is that for any given motion, there must be some mover that possesses the necessary actuality to cause the motion of itself, and not in a purely derived/instrumental way. All of this I myself have claimed in my book Nature and Nature’s God.

How, then, does the First Way conclude to God, as its last sentence indicates it does? There is a basic difference between the way Aquinas thinks about proving God’s existence and the way contemporary philosophers of religion do. Aquinas contrasts on this score with Scotus, who is more like our contemporaries. Scotus does not think that God’s existence has been proved until the existence of a unique, infinite being who is the first efficient cause, most eminent being, and ultimate final cause has been proved. For this reason his proof for God’s existence is very long. Aquinas, by contrast, does not think that very much is implied in the mere word “God”/”god”. The ancient Romans called the emperor a god, and the planets, and in some cases even the elements. God is a name for whatever rules the universe, in the sense of determining what goes on in it. By proving that there are one or more first movers, Aquinas proves that someone or some persons, or even something or things rules the universe. So the First Way has to do very little to prove the existence of God or gods. Aquinas’ strategy, by contrast to Scotus and our contemporaries, is to prove the existence of God in a very minimal sense, and then to progressively determine more and more about the attributes of that being that is called God, until He looks very much like the God that Christians worship.

But Aquinas’ claim that “this all call God” is made further understandable by the cosmological context in which he was writing. In the medieval understanding, motion here on earth was crucially dependent on the motion of the heavenly bodies. The heavenly bodies, in turn, must be moved by something, either a soul or a completely immaterial being. Those souls or immaterial being or beings would be the most obvious candidates for the first, unmoved movers of any motion here on earth. No one would have hesitated in the ancient world to call them gods. Aquinas knows that the logic of the First Way does not itself show that such souls or immaterial planet movers exist, only that one or more unmoved movers exists. So he does not draw any stronger conclusion than his logic warrants. But whatever is in fact a truly unmoved, first mover would be a kind of god, so the argument does show that one or more gods exists. It will turn out, given subsequent argument, that there is only one truly unmoved mover, and that He is completely immaterial. So the general conclusion of the First Way is never undercut, only progressively determined.

The First Way, in its basic structure, is based on Aristotle’s argument in Physics VII. Aquinas also provides an argument with the same structure in the Summa Contra Gentiles (what Kretzmann called G1). But in the latter work he also provides another motion proof (G2) that is based in its structure on Physics VIII. In his commentary on Aristotle’s Physics, Aquinas states twice that the argument in Physics VII shows that there is an unmoved mover, whereas the argument in Physics VIII shows what sort of being an unmoved mover is. We don’t get anything resembling what contemporary philosophers of religion think of as God (as opposed to the sort of thing a pagan might call a god) out of the First Way by itself. It is, rather, the first step in a longer argument. It is extended by the Third Way, or by the parallel argument G2. I explore both of these latter arguments in my book, but especially G2.

The Third Way and G2 turn the argument towards the possibility of an infinite accidentally ordered causal series and a beginningless universe. There it is argued that without an eternal, necessary being to sustain it, there cannot be an infinite accidentally ordered causal series. The conclusion, made explicit in G2 in the Summa Contra Gentiles, is that if the universe had a beginning, then an immaterial eternal God must exist to start it, and if the universe has no beginning, then an immaterial eternal God must exist to sustain it in motion. Otherwise it would come to rest (in modern terms, it would reach a condition of thermodynamic equilibrium) within a finite time. If the universe has no beginning, then an infinite time has already elapsed and the universe would be at rest already, if no God were sustaining it (the world would already be in a state of heat death.) This proves that God exists. It does not prove that the universe has a beginning.

Other authors should certainly continue to defend their interpretations of Aquinas’ argument. But it looks to me that my book is exactly what is needed to respond to Schmid and Linford’s criticisms.

My colleague at Wyoming Catholic College, Dr. Paul Giesting, graciously interviewed me about my book on Aquinas’ First Way, Nature and Nature’s God. The podcast can be found here. Check it out, and if you are interested, buy the book while it is still on sale at the CUA Press website (discount code THEO23).

Until mid-July my book on Aquinas’ First Way, Nature and Nature’s God, is on sale for 30% off from the CUA Press website: https://www.cuapress.org/9780813236674/nature-and-natures-god/. Use code THEO23 when checking out. The book is scheduled to be released July 7th. I’m grateful for Rob Koons, Travis Dumsday, and Fr. Davenport for their reviews.

Nature and Nature’s God is now available for pre-order: https://www.cuapress.org/9780813236674/nature-and-natures-god/.

An article was recently published online in the International Journal for Philosophy of Religion by Thomas Oberle titled “Grounding, Infinite Regress, and the Thomistic Cosmological Argument.” Oberle criticizes Aquinas’ argument against infinite regress as question begging.

Oberle recognizes the distinction between essentially and accidentally ordered causal series, and with it the difference between derived and underived causal power. He maintains, however, that the Thomistic argument fails because it equates a finite essentially ordered causal series without a first, underived cause (such as a few boxcars connected to a caboose) and an infinite essentially ordered causal series without a first, underived cause. The former is clearly impossible because it would involve the existence of a cause whose causal power was neither underived nor derived; the cause at the head of the series does not have derived causal power because there is no prior cause to derive it from. An infinite essentially ordered series, however, involves no such absurdity, for every cause has a prior cause from which it derives its causal power, and so there is no cause without at least derived causal power. How do we know that there cannot be an infinite series of borrowers with no owner, Oberle asks?

But despite acknowledging the distinction between essentially ordered and accidentally ordered causal series, Oberle fails to fully appreciate the nature of essentially ordered series. His reasoning implies that having derived causal power renders a secondary cause a sufficient cause of the effect in question, whereas the kind of causal subordination of which Thomists speak means that the secondary cause is not a sufficient cause of the effect. The secondary cause is a conduit for causality; without a first cause with underived causal power, there is no cause of the effect.

Perhaps the example of the train and the related example of a man who moves a stone with a stick could mislead here. If the boxcar and the stick had the requisite kinetic energy, whether they got it from somewhere else or not, they could move the caboose and the stone by themselves. (Although to move the stick or the caboose uniformly, as in the examples, they would have to have a store of potential energy and the ability to convert it themselves, so as to maintain a constant velocity in the resisting caboose and stone; in other words, they would have to be something like engines.) The example of links in a chain holding up an engine block better illustrates Aquinas’ notion of an essentially ordered series. The link attached to the engine block simply does not hold up the engine block, even though it has derived causal power to do so. Neither does the link above it. Only the hoist holds up the engine block, for only there does one find the causal power to do so. If there were no hoist, but only an infinite series of links in a literal chain, the whole chain and the engine block would fall.

Hence infinite essentially ordered causal series are impossible. Without a first cause there is no causality at all, whether derived or underived. Given the nature of derivative causal power in an essentially ordered series, there is no derived causal power without an underived causal power. Derived causal power is derived not from the immediately prior cause in the series, but only from an underived causal power that can terminate the series.

Alleluia! Roe vs. Wade was overturned this morning, on the Solemnity of the Sacred Heart! So many people have prayed so hard for so long for this. Nothing this good has happened to this country in my lifetime! Today is a day to celebrate! God is good!

At the ACPA conference last month, Harrison Lee of Baylor delivered a paper (“Two Objections to a Broad Scope Theory of Intention,” which will appear in the Proceedings of the American Catholic Philosophical Association) raising objections to some Thomistic theories of intention, including my own. Lee argues that my claim that essential consequences of an intended action fall under the scope of the intention ends up reducing to the claim that statistically likely and thus expected consequences of an action fall under the scope of the intention. In this way the principle of double effect becomes useless, because one can no longer distinguish between intended and foreseen bad effects. (My account of intention was presented at a book panel discussion of Larry Masek’s Intention, Character, and Double Effect at the 2019 ACPA conference–available on the “Writings” page of this site–later revised as a book review in the ACPQ.)

I would resist the claim that on my account, the essential consequences of an action (those consequences which are per se in the 4th mode) reduce to those consequences that are statistically likely. Correlation does not imply causation, and a fortiori it does not imply essential causation. However, when a correlation is observed, it is reasonable to suspect causation. Correlation prompts one to investigate and look for the connection between two items. Perhaps the one is the cause of the other, or vice versa; perhaps they are both effects of the same cause; perhaps the one item is somehow concomitant with a third item which is the true cause of the other; etc. In the case of an action and its consequences, to establish essential causation (that the consequence is predicated of the action per se in the 4th mode), some sort of conceptual insight is required, by which one sees that the action, in virtue of what it is, produces that effect, even if the effect can be impeded by external factors.

At the time of my panel presentation, however, I had not sufficiently clarified in my mind the relationship between statistical likelihood and essentiality. Lee recognizes an inconsistency/weakness in my answer to one of Masek’s objections. Masek had brought forward an example of an adult son with a stutter who must testify on behalf of his father. He knows that he will almost certainly stutter as he testifies and thus weaken the persuasiveness of his testimony. Masek claims that it is unreasonable to suppose that the son intends to stutter just because he knows that stuttering is closely and inevitably joined to his intended act of testifying. In my presentation I claimed, unreasonably, that the son does intend to stutter, because “he knows that for him stuttering is essential to the act of speaking, for he always or usually stutters when he speaks.”

I see now that the son does not intend to stutter, nor is stuttering an essential consequence of his intended action of speaking on behalf of his father. One can see that the connection between speaking and stuttering is not essential even for him, for other people do not stutter when they speak, and it is clearly a result of an unusual condition he has. So the connection between his speaking and stuttering is mediated: it is a consequence of two things, his intention to speak coupled with his condition. It is a mere accident that the condition and the intention are coupled in his case, because in most people the condition is not present although the ability to speak is. This accidental conjunction of the ability to speak with the psychological or physiological condition produces a strong correlation between his speaking and his stuttering. But since the stuttering son does not will his own condition, the stuttering that it co-causes does not fall under his intention; it is not an essential consequence of his intended action. The stutter is a clear case of what Thomists would consider a natural defect, in which the natural effect is not well achieved. Thus the proper moral analysis of his situation is that he knows that he is risking stuttering. In fact he knows that it is highly likely that he will stutter, and he must perform a cost-benefit analysis of this unintended effect compared to the benefits that could be achieved by acting. And the cost-benefit analysis comes out in favor of speaking.

A similar analysis, with the opposite conclusion, would apply to another example Lee brings up in this context: that of a man who commits manslaughter by driving home drunk. He does not intend to kill when he gets in the car, nor is killing an essential consequence of his action. The action is one of driving, and driving does not in and of itself tend to kill human beings. However, the circumstance of drunkenness significantly increases the likelihood of accidentally killing, and thus the drunk man is knowingly taking a big risk of harming people. The cost-benefit analysis comes out strongly against taking the risk, and thus it is highly irresponsible to take the risk. If the drunk man fails to fulfill his intention of driving home safely, he has committed manslaughter-unintentional but reprehensible killing–but not murder–intentional killing.

I am grateful to Lee for his criticisms, as they have helped me to see what was wrong with my presentation. What I previously said about the stuttering son example likely produced a misunderstanding in the minds of many about the nature of my position. I am also interested to see where Lee is going with his project.