One of the most common critiques of Thomas Aquinas to be found in contemporary Protestant theology and apologetics is that Aquinas either outright denies the noetic effects of sin (that is, the effect of original sin on the human intellect) or at least minimizes the noetic effects of sin. Francis Schaeffer, for example, explicitly states, “In Aquinas’s view the will of man was fallen, but the intellect was not.”1 This critique, that Aquinas’s incomplete understanding of the noetic effects of sin opened the door to an unwarranted confidence in the ability of the human intellect to somehow infer the existence of God from nature, appears to be a fairly recent development in the history of Reformed critiques of Aquinas, finding its roots, according to some, in the work of Herman Dooyeweerd.2 In his 1959 book Roots of Western Culture, Dooyeweerd describes the scholastic view, of which Aquinas was apparently the “Prince,” as suggesting that the fallen “human ‘nature,’ which is guided by the natural light of reason, was not corrupted by sin and thus also does not need to be restored by Christ. Human nature is only ‘weakened’ by the fall.”3

Even though some scholars (both Catholics and Protestants) have attempted to correct this misinterpretation of Aquinas,4 the misunderstanding persists and maintains its popularity in many Protestant circles. This can be seen clearly in the recent publications of K. Scott Oliphint, who states,

During the Middle Ages, insufficient attention was given, in general, to the problem of sin as it relates to our reasoning process…. Because the effects of sin were thought to be less extensive in their application to us (as compared with Reformation thought), in that sin was not seen as radically affecting our reasoning, there was an improper view of the faculty of reason, especially with respect to reason’s ability to understand and discern God’s revelation and his existence. Reason was regarded as fairly well intact, even after the fall, such that all men followed the same basic rules of thought.5

These claims are summarized in his 2017 book on Aquinas: “what the medievals, including Thomas, neglected to incorporate in their theological system was the radical effect that sin has on the mind of fallen man.”6 Oliphint does not stray far from Cornelius Van Til, who portrays the Roman Catholic view of the noetic effects of sin as follows: “According to this view the disturbance is endemic to human nature because man is made up, in part, of nonrational elements. To the extent that man consists of intellect, he does not and cannot sin. The ‘disturbance’ in man’s make-up is not due primarily to any fault of his own.”7 Whether or not some Roman Catholic theologians may have affirmed such a claim, we will argue that Aquinas did not.8

It is the primary purpose of this article to provide a much-needed corrective to these all-too-common and continually repeated misinterpretations of Aquinas that continue to be promoted by contemporary Protestant theologians and apologists. In this article I show not only that Aquinas clearly states that human nature in its entirety (i.e., both intellect and will) is affected by sin, but also that his approach can be adopted by Protestant theologians without sacrificing Protestant particularities. First, I overview Aquinas’s approach to human nature and faculty psychology. Second, I turn to his understanding of sin (actual and original) in order to show not only that he clearly thinks that man is totally depraved (such that original sin affects even reason), but that his views concerning the nature and transmission of original sin entail that man is totally depraved. Aquinas’s understanding of the interrelation of the intellect and will is essential for a proper understanding of his claims concerning the noetic effects of sin. In the process, I show how Aquinas’s articulation of the effects of sin on the entire human nature includes not only intellect and will, but all of those faculties that can be moved by the will to act.

1. Aquinas on Human Nature

How a theologian articulates the doctrine of original sin, and the effects of original sin on the human being, will be strongly influenced by their understanding of human nature. It is necessary, then, to understand Aquinas properly, to begin with a summary explanation of Aquinas’s approach to human nature.

1.1. Hylemorphism

First of all, a substance, for Aquinas, is a particular existing essence. An individual human, Socrates, is a particular instance of the human nature. Socrates is, therefore, a substance. Socrates, is not, for Aquinas, a soul in conjunction with a body (two separate substances), but a single unique substance composed of two substantial parts (the rational soul and designated matter—his body).9 Though we can distinguish between the substantial parts, matter is part and parcel of human nature, and, therefore, of the “person”—that is, what we talk about when we think of the seat of rationality, consciousness, action, and so on, is the single, unique, substance that is composed of soul and body. For Aquinas, it is the whole substance (not the soul alone) that is the “person.” The unity of the human person is a necessary and fundamental element of any discussion of human nature, the human person, and the morality of human action. Aquinas’s hylemorphism puts so much emphasis on the human being as “informed matter” or an “ensouled body” that some contemporary philosophers have had trouble deciding whether to classify it as a form of materialism (attribute theory) or a form of dualism.10 This must be kept in mind whenever we read Aquinas on human nature, human action, etc.: the human person is a single united particular instance of human nature. We can abstract from the person for the purpose of theory, but the reality that is in act and which acts is not the abstraction, but the individual embodied soul.

1.2. Human Action: Faculties and Habits

Aquinas’s approach to human action has often been described as a “faculty psychology.”11 Understanding Aquinas’s approach to human action is the next step in understanding his view of the effects of sin (both original and actual) on human nature and human actions. There are two major terms that we need to understand in order to grasp Aquinas here: Powers or Faculties and Habits.

First, a “power” or “faculty” is a principle of activity that is directed to an act.12 Aquinas notes, “a power of the soul is nothing else than the proximate principle of the soul’s operation.”13 A power can be described in relation to the first act of a living being—the soul, which is the substantial form of the individual human being, as the second act of a living being.14 We discover the nature of a power by considering the act, which finds its source in the power, towards which the power is directed (for the most part).15 Such a consideration of human action allows us to distinguish between passive and active powers,16 and the five genera of the powers: (1) vegetative, (2) sensitive, (3) locomotive, (4) appetitive, and (5) intellectual. The powers proper are classified under the five genera as follows:

1. Vegetative: generative, augmentative, nutritive
2. Sensitive: interior senses, exterior senses
3. Locomotive: outer movement
4. Appetitive: Intellectual appetites (will & choice), Sensuality (Irascible and concupiscible appetites)
5. Intellectual: Active (reason and understanding), passive (memory).

The appetitive faculties could also be referred to (shorthand) as the will, and the intellective faculties could be called intellect/reason. The appetitive power is a “special power of the soul,”17 which can be simply described as the tendency to the perceived good.18 For Aquinas, the human will can be distinguished into the “sensible” and “intellectual appetites”, but, in both cases, as human, the will is informed and directed by reason.19 More could be said, here, but this should be sufficient to allow us to grasp what Aquinas is doing.

Second, a “habit” is that by reason of which we are well or ill-disposed with regard to actions and passions.20 Habits can be distinguished from powers in the following manner: “by a power man is, as it were, empowered to do the action, and by the habit he is apt to act well or ill.”21 Habits are formed through repeated acts of a certain type. We might sum up the notion of a habit as follows: a habit is a quasi-permanent tendency towards a certain actualization of a power that allows a person to act immediately (without reflection), when the appropriate stimuli are present; and to perform that act either rightly (virtuously—from whence the virtue) or wrongly (viciously—from whence the vices). A vice is a habit that tends towards a wrongful act; a virtue is a habit that tends towards a right act.

We need a quick reminder before we move on: though Aquinas distinguishes (1) between the powers, intellect, and will, and (2) between the principles from which a person acts (powers/faculties) and that by which the person acts, without reflection, either rightly or wrongly (the habits), he nevertheless views the action of a human person as the effect of a single united individual. It is the person who acts, the whole person, not a part. We must not, contra some reformed critics of Aquinas, and even some Catholic Thomists such as Bernard Lonergan and R. J. Snell, see these distinctions as creating some sort of absolute fracturing of the human person such that one can act sinfully, or be affected by original sin, in one faculty, without this also both (1) affecting the whole person and (2) being an act of the whole person. To see, this, however, we now need to turn to Aquinas’s treatment of actual sin and of original sin.

2. On Sin and Human Action

Having briefly considered Aquinas’s understanding of human nature and human actions, we turn now to what constitutes the properly human act, and Aquinas’s explanation of how humans are effected by sin: actual and original.

2.1. The Properly Human Act

Following Aquinas’s development of this issue in the Summa Theologiae, we begin by noting that human actions, properly so called, are those which are proper to man as man. A human is, according to Aquinas, a rational animal;22 which means, not that man is some sort of rational Cartesian ghost in a machine, but, rather, that everything that man is and does is informed by reason.23 For example, Aquinas thinks that will and choice (the intellectual appetites) in man, are what they are because man is a rational animal. With this in mind, if we look at the actions done by a human being, some actions are done without deliberation (breathing or scratching an itch); but, others are done only after some deliberation (or, based upon deliberately formed habits).24 The former are not proper to humans as humans, while the latter— actions based upon deliberation—are. It follows, then, that properly human actions are those “which proceed from a deliberate will,”25 for “man is the master of his actions through his reason and will.”26 We can summarize this as follows: a properly human action is a voluntary and deliberate action.27

2.2. Of Sin, Sins, and the Subject of Sin

No, this is not a grammatical error. The word “subject” here refers to “that in which something adheres.” Aquinas, in his articulation of sin, takes time to not only explain what sin is in relation to properly human acts, but to distinguish between types of sin based upon their “subject.” A sin, for Aquinas, is “an inordinate act.”28 Thus defined, an objection might be raised: what then of “sins of omission”?29 Aquinas’s answer to this question helps us to better understand what is meant by the definition of sin as any “inordinate act.” We are not talking about the concept of original sin yet. We are dealing with the question, What is true of every single action (interior or exterior) which is sinful? Answer: in some way, it breaks the divine law.30

First of all, says Aquinas, if “we look merely at that in which the essence of the sin consists, the sin of omission will be sometimes with an interior act … while sometimes it will be without any act at all.”31 Furthermore, if “we consider also the causes or occasions of the omission then the sin of omission must of necessity include some act.”32 That is, when we consider the causes or occasions of the omission that is sinful (that is, a failure to act when one should have acted), we realize that some other act is the cause of the sin of omission. For example, we may be obstructed from performing act A because we have decided to do act B instead; or we may be obstructed from performing act A at time₂ as a consequence of having decided to perform act B at time₁. In both of these cases, the subject—the individual human person—voluntarily performs act A, and it is because of the performance of act A that they are kept from performing act B—which they should have done. The result is a “sin of omission”—not doing what they should have done.33 Thus, even when there is no voluntary action at the time of the omission, the sin of omission is caused by some voluntary action. It is also worth noting that exterior action is related to the “interior act.” In other words, Aquinas is not simplistically confining sin to “exterior actions” but recognizes full well that there are interior sins (even if they don’t issue into exterior acts).34 This discussion drives home Aquinas’s point, which is, for a wrong action to be sinful, it must be voluntary.35

Aquinas goes on to ask the question, “what is the Subject of Sin?” That is, in what does sin inhere, or in what is sin found?36 That sin, by nature, is an inordinate act will be the guiding principle for Aquinas’s answer to this question. Aquinas proceeds as follows: if sin is, by nature, an act, then “the proper subject of sin must needs be the power which is the principle of the act.”37 An act, to be properly human (and moral) must be voluntary—flowing from the will. “Now,” says Aquinas, “since it is proper to moral acts that they are voluntary … it follows that the will, which is the principle of voluntary acts, both of good acts, and of evil acts or sins, is the principle of sin.”38 In other words, if “to sin” is “to act wrongly,” or “to act inordinately,” or to act against the divine law in some way shape or form (whether the act is an exterior or interior act), and if all properly human acts proceed from the will, then it follows that the will is the “principle” of sin. The will, then, is the subject of sin—that in which sin is primarily found.

This conclusion may be one of the reasons why some scholars have thought that Aquinas did not think that sin had affected (or could flow from) the intellect or human reason. One should ask, however, “does this mean that sin is only in the will?” I would suggest we keep reading and not close our copy of the Summa triumphantly, having found another reason to reject Aquinas; for Aquinas answers this apparent problem in the very next question. Is sin found in the will alone? Aquinas’s answer: no, sin is found in any power of the soul that can be moved to, or restrained from, its proper act by the will. As we have already seen, the powers/faculties each have their proper act. They also have their own proper end, which is the good towards which they tend. For example, the intellect tends towards truth as to its end; the will tends to the good perceived; the irascible appetite tends to the difficult good; the concupiscible appetite tends to the pleasurable good.

Let’s go deeper. In rational animals, Aquinas suggests, there is an interaction (perhaps we could talk about interchanging and related roles) between intellect and will,39 which brings us to the conclusion that in one way intellect is prior to will, but that in another way, will is prior to intellect. Intellect is prior to will in that it perceives and presents to the will the good to be pursued—moving the will, therefore, as final and formal cause.40 Will is prior to intellect in that it moves the intellect to pursue its proper object—the truth—as an efficient cause.41 Thus, inasmuch as the will is said to move the intellect to pursue its proper end or good (truth), the intellect is said to be moved to act by the will.42

Similar points can be made about each of the other powers/faculties of the soul. Let’s not forget, whenever there is an act done by a rational animal that act may be ordinate or inordinate. Inordinate act is sin. Thus, all the powers/faculties of the human person, insomuch as they are moved by the will to act, are also subject to sin. It follows, then, that though the will is primary (as it is the will that moves the powers to act) in relation to sin, sin is found in each of the faculties as in a subject. Another quick reminder, it is the human person—a substantial unity—who acts (the will directing the powers, forming habits, etc.). Thus, in any sin, it is the entire person who sins. This is one way in which we demonstrate that the entire soul—every faculty and power—is subject to sin.43 Aquinas goes on to show how sin is in each of the powers.44

We won’t look at each power/faculty individually, though it is worth noting some of the general principles that Aquinas uses to prove that sin is in each of the faculties as in a subject. For example, he notes, “sin may be found in any power whose act can be voluntary and inordinate.”45 “The sin of any power is an act of that power.”46 All human acts can and should be governed or regulated by two rules: (1) divine law and (2) human reason.47 Consent to an action (good or bad) is both an act of the will and of reason. In relation to the will, “consent is an act of the appetitive power, not absolutely, but in consequence of an act of reason deliberating and judging.”48 As to reason, “consent implies a judgement about the thing to which consent is given. For just as the speculative reason judges and delivers its sentence about intelligible matters, so the practical reason judges and pronounces sentence on matters of action.”49 Sin, then, is in all of the faculties, but primarily in the will—by which man is moved to action. To deny that Aquinas places sin in reason should be seen, therefore, as not just a “misreading” of Aquinas, but as what Aquinas would call “culpable ignorance”—we should know the truth, but we willingly either deny it, overlook it, ignore it, or distort it.

2.3. On Original Sin

To prove that Aquinas has a robust and profound understanding of the noetic effects of sin, it is not enough to prove that he situates actual sins in reason (as their subject and principle). One must also prove that reason is itself corrupted by the fall. To do this we turn to his understanding of original sin. What, then, is original sin, and does it affect reason in all humans? As with his explanation of particular actual sins, the answer to this question is obvious to any who take the time to actually read Aquinas. In short, Aquinas agrees with Augustine, against Pelagius, that all humans are infected and corrupted, via generation, in the entirety of their nature, by original sin. To get there, we need to read through three questions, where Aquinas considers three aspects of original sin: (1) its transmission, (2) its essence, and (3) its subject. We will look rapidly at each of these questions in order to gain a proper understanding of Aquinas’s views. What we will find is that in each of these subjects, Aquinas clearly affirms the corruption of the entire human nature—not just one part of the human nature, such as the will.

2.4. The Transmission of Original Sin

For Aquinas, the doctrine of original sin is based in part on Romans 5:12–21, which claims that through the sin of one man all men sin, and therefore, death spread to all men.50 One of the most important questions related to original sin, in light of Romans 5:12, becomes how did it so spread? Throughout the history of the church, and in both Protestant and Catholic churches, there have been different theories on both the nature of original sin and on the nature of its transmission. Aquinas, following Augustine, argues that original sin is transmitted from Adam to all of his descendants,51 through the human nature, corrupted by the fall—by way of origin.52 For Aquinas, though the human nature is corrupted and some form of guilt is transmitted, the guilt of the actual sin of Adam is not transmitted; for men are guilty only of those sins which they actually commit. There is, however, for Aquinas, a form of “guilt by association”—by the fact that we share the same nature, and are thus in Adam, we share in Adam’s guilt.53

Therefore, as original sin is tied to human nature, as a “stain which infects it,” and human nature is transmitted to the next generation through the semen, it follows that original sin—the stain which infects human nature—is also transmitted by the semen54 and, furthermore, by our generation from Adam we are associated with him in his guilt. It follows from this that “original sin” was transmitted to all men who are descended from Adam—with one exception.55 Aquinas’s argument for this claim is that if this was not the case, then not all men would be in need of Christ’s redemptive work on the cross. However, all men, except Christ, need redemption. Therefore, all men are corrupted by original sin.

In sum, original sin is a stain on, or a corruption of, human nature (such that the entire nature is affected, and all men are affected from conception), and it is, therefore, transmitted to all the descendants of Adam, via generation, such that all men, Christ excepted, are affected by the stain of original sin and associated with the guilt of Adam, through one human nature. Not only do we inherit this stain, infection, corruption, or disorder of our nature,56 and guilt by association, but we also lost, according to Aquinas, “original justice,” which was given to man at creation, as a special grace.57

2.5. The Nature of Original Sin

In sum, we can say that, for Aquinas, original sin is (1) an inherited “stain,” “infection,” “corruption,” “defect,” and “disorder” of the human nature itself,58 (2) a sharing in the guilt of Adam—not as having committed Adam’s sin, but by association with Adam, and (3) a loss or deprivation of original justice.59 We have already seen what Aquinas means by the first two parts of this description, so we will explain the last element as we delve a bit deeper into just what original sin is by nature. The notion of “original justice,” and its loss through Adam’s sin, for Aquinas, has to do with man’s ability (or, inability) to fully submit to God.60 Aquinas describes the loss of original justice as “removing the subjection of man’s mind to God.”61 Original justice was a grace that was given to man in Adam,62 by which the will of man was subject to God.63 With the loss of original justice in original sin, the will turned away from God to mutable goods. It could be said that by this turning away from God, “all the other powers of the soul become inordinate.”64

This loss or privation of “original justice” has been the cause of some debate, such that some scholars think that when Aquinas says that original sin is the loss of “original justice” Aquinas is saying that the human nature remains entirely intact and that original sin is nothing more than the loss of something which was, in any case, extrinsic to the human nature. This is most certainly not what Aquinas is saying. He very clearly maintains that original sin is an infection and corruption of human nature (not just the loss of an extrinsic grace) when he says, for example, “original sin, being the sin of nature, is an inordinate disposition of nature.”65 Furthermore, “Original sin infects the different parts of the soul, in so far as they are the parts of the whole.”66 Or again, “Original sin is a sin of nature, infecting the whole nature and all those who possess that nature.”67 In relation to these elements of original sin, Aquinas suggests that the “formal element” of original sin—the loss of original justice—is a rebellion of the human will against God and an inordinate turning of the human will away from God (man’s ultimate good) to mutable goods.68 The “material element” of original sin then would be the disordering of the soul’s powers by which they turn to mutable goods rather than God.

Delving deeper into the nature of original sin, Aquinas calls again upon Augustine as authority, suggesting that original sin is a type of habit—or, perhaps better, that it has the character of a habit. We have seen that a habit is a learned tendency of a natural power (learned via repetition) by which the power tends as if by nature (always or for the most part) to the performing of some act in a way that is either good (virtuous) or bad (vicious). This is, for Aquinas, the primary sense of the term habit,69 but it is not the sense in which original sin is like a habit. Rather, suggests Aquinas, there is a second sense of the term “habit,” by which we understand the nature itself (not just one power/faculty, but the whole nature) to be “well or ill-disposed to something”—that is, when a disposition “has become like a second nature.”70 It is in this second way that original sin is said to be a habit—that is, a disposition of the entire human nature by which man is, as if by nature, disposed towards inordinate acts (sin). Not just a part of man, but the whole nature is disposed to sin.

Original sin so corrupts human nature and disposes man to sin, that Aquinas can argue that (a) “all actual sins [all those sins that are actually committed by a real person] virtually pre-exist in original sin, as in a principle”71—that is, all those sins that are actually committed by a person flow from the corruption and disordering of human nature which I, as a particular human being, have inherited from Adam. (b) Aquinas also reminds us that every part of the soul is infected by original sin—every power or faculty. In his response to the third contrary position, Aquinas notes, “Original sin infects the different parts of the soul, in so far as they are the parts of one whole.”72 That is, just like a little poison, if mixed into the filling of a pie, infects the whole pie, and thus all of the pieces of the pie as parts of that pie (such that regardless of which piece you eat you will be poisoned); in the same way, original sin has so infected the whole human nature, and thus all of the parts as parts of that one nature—that it matters not which part you consider (i.e., will, intellect, sensibility, etc.), it is infected and corrupted by sin. This is what is generally meant by the doctrine of total depravity—not that through original sin man is absolutely depraved (or as depraved as he can be), but that through original sin no part of human nature remains untouched or uncorrupted.73 This of course entails that all men born of Adam are equally infected and corrupted by original sin (though this corruption shows itself differently in different individual humans).74

2.6. The Subject of Original Sin

When we consider the subject of original sin, suggests Aquinas, we can consider it in relation to its “inherence in the subject”—that is, the way in which it is found in the individual human being; or we can consider it in relation to the individual being’s “inclination to act”—that is, how original sin affects the particular actions of a particular human. Considered in the first way, original sin can be said to be in our body as in an instrumental cause75 but is properly said to be in the soul (the substantial form of the human person) as in a subject76—thus, the whole nature is stained, the corruption is complete. If it is considered in the second way, original sin is “primarily” in the will. This is due to the fact that, as we have already seen, in relation to actual sin, all human action flows primarily from the will, as it is the will that moves the other powers to pursue their proper ends and perceived goods.77

For Aquinas, humans have will and free choice specifically because they are, by nature, rational animals. Original sin is in the rational soul as its subject; thus all the rational powers of the rational soul (as has already been shown) are corrupted by original sin—insomuch as they are moved by the will; and they are all “punished” insomuch as they are used in the sinful actions as instrumental causes. It is the primacy of the will in action that leads Aquinas to say that the will is the primary subject of original sin.78 When Aquinas says that original sin is primarily in the will, he says this in relation to the actual sins committed by an individual person. For what moves an individual to commit an actual sin is their will which, presented with actual goods to be pursued, moves the person by the relevant powers to obtain the good that is most desired (by that individual—not necessarily the good which is most desirable per se). However, this is not to say that the whole nature, and thus intellect or reason, is not (or is less) affected by original sin. Rather, it could be said that the will is so infected just because it is part of the nature, which is fully corrupted by and is the proper subject of, original sin.

3. Conclusion

We set out, in the first place, to refute and bury, once and for all, that persistent Protestant rumor that Aquinas allows for the corruption of the human will, but that he let reason get away scot-free. This claim is, in light of a proper reading of Aquinas, not only false, but so clearly false that one could almost be accused of dishonesty for propagating such an idea. The fact that it has persisted in Protestant theology for so long is shameful, and it is my hope that this paper will go some distance to correcting this unfortunate twisting of Aquinas’s thought.79

Beyond correcting this misreading of Aquinas, I hope that these reflections will lead to a deeper understanding of human nature and sin and, in this way, to a practical application of this knowledge in Christian counseling and personal sanctification. I have labored to show that Aquinas’s approach to human nature begins and ends in the concrete, particular human individual. It is not the faculty that sins, but the person through the faculty. In addition, Aquinas’s approach to human nature (noting the interaction of intellect and will, the formation of habits, the tendency of the powers towards their proper ends, and the role of the will in directing each power to its proper end) provides us with the ability to introspectively analyze our own actions, thus discovering why we do certain things (right or wrong), and how we came to so act.

---

[1] Francis Schaeffer, Escape from Reason, reprint ed. (Downers Grove, IL: InterVarsity Press, 1974), 11.

[2] Cf. R. J. Snell, “Thomism and Noetic Sin, Transposed,” Philosophia Christi 12 (2010): 7–10; Arvin Vos, Aquinas, Calvin, and Contemporary Protestant Thought (Washington, DC: Christian University Press, 1985), 131.

[3] Herman Dooyeweerd, Roots of Western Culture, trans. John Kraay, eds. Mark Vander Vennen and Bernard Zylstra (Toronto: Wedge, 1979), 116–17. Cf. Dooyeweerd, In the Twilight of Western Thought: Studies in the Pretended Autonomy of Philosophical Thought (Philadelphia: P&R Publishing, 1960), 140.

[4] Cf. Arvin Vos, Aquinas, Calvin, and Contemporary Protestant Thought: A Critique of Protestant Views of the Thought of Thomas Aquinas (Grand Rapids: Christian University Press, 1985); Snell, “Thomism and Noetic Sin”; R. J. Snell and Steven D. Cone, Authentic Cosmopolitanism (Eugene, OR: Wipf & Stock, 2013).

[5] K. Scott Oliphint, Covenantal Apologetics: Principles and Practice in Defense of Our Faith (Wheaton, IL: Crossway, 2013), 128.

[6] K. Scott Oliphint, Thomas Aquinas, Great Thinkers (Phillipsburg, NJ: P&R Publishing, 2017), 33.

[7] Cornelius Van Til, The Defense of the Faith, ed. K. Scott Oliphint, 4th ed. (Phillipsburg, NJ: P&R Publishing, 2008), 97.

[8] There is a second contemporary critique of Aquinas that can be dealt with at the same time, coming this time from an advocate of Thomistic thought. R. J. Snell suggests, “Aquinas is constrained by a faculty psychology” (Snell, “Thomism and Noetic Sin,” 18). How is Aquinas constrained? Snell, under the influence of Bernard Lonergan, argues, first that Aquinas’s faculty psychology “risks treating our faculties almost like reified parts which need piecing together, harmoniously or otherwise (18). That is, Aquinas’s psychology so divides man up that we lose sight of the unity of the human person, which, thinks Snell, opens Aquinas up to the accusation that the will alone, and not the whole person, is infected by original sin (19). Second, argues Snell, Aquinas’s faculty psychology “risks neglecting the concrete, conscious subject, that is, the actually existing person” in favor of a metaphysical abstraction (18). Aquinas, according to Snell, fails to account for the lived experience of the concrete subject—the conscious self, and “the things concrete human beings do when they reason,” “how reason works in the concrete,” or the “operations of consciousness” (20). These two main critiques bring Snell to the conclusion that a faculty psychology “overlooks the consequences of sin” on the concrete person (20). Snell concludes that Aquinas’s psychology needs to be supplemented by, or worse, transposed into, Lonergan’s “introspective phenomenology” (20). He thinks that this transposition will resolve the complaints of the Neo-Calvinists. I would suggest that a proper reading of Aquinas demonstrates that each of Snell’s critiques are unfounded, and, therefore, that there is no need for any phenomenological supplements or transpositions.

[9] Though it is doubtful that John Calvin was a hylemorphist (which is what the approach to human nature associated with Aristotle and Aquinas is called), it is clear from the Institutes that he agrees, in general, with this portrayal of human nature. For he says, “Moreover, there can be no question that man consists of a body and a soul; meaning by soul, an immortal though created essence, which is his nobler part” (John Calvin, Institutes of the Christian Religion, 1.15.2, trans. Henry Beveridge, reprint ed. (Peabody, MA: Hendrickson, 2012), p. 104). Calvin goes on to discuss the nature of man and the human faculties, admitting that even pagan authors have described human nature better and more eloquent than he does (1.15.2, p. 105; cf. 1.15.3, p. 107; 1.15.6, p. 109).

[10] Cf. D. M. Armstrong, A Materialist Theory of the Mind, reprint ed. (London: Routledge & Kegan Paul, 1971), 12.

[11] Though I will not go into any detail in considering Calvin’s psychology, he clearly also held to what would be broadly called a “faculty psychology.” In fact, he suggests that it is not possible to truly grasp what is meant by saying that man is made in the image of God until “it appears more clearly what the faculties are in which man excels” (Institutes, 1.15.3, p. 107). Calvin goes on to explain in a manner that is very Thomistic (though the resemblances can be traced through Aquinas all the way back to Augustine and beyond to Aristotle) that there are five senses (1.15.6, p. 110), three cognitive faculties of the soul: Intellect, Imagination, and Reason; and that there are three appetitive faculties: will (“whose office is to choose whatever reason and intellect propound”), irascibility, and concupiscence (1.15.6, p. 110). For other Reformed theologians who hold to a faculty psychology, see Chad Van Dixhoorn, Confessing the Faith: A Reader’s Guide to the Westminster Confession of Faith (Carlisle, PA: Banner of Truth Trust, 2014), 83; L. Berkhof, Systematic Theology, 4th ed., reprint ed. (Grand Rapids: Eerdmans, 1979), 195–96.

[12] ST I, q. 77, a. 1, ad 3; Questions on the Soul, q. 12, resp., p. 156. All quotations from the Summa Theologiae, unless otherwise noted, are from the following translation: Thomas Aquinas, Summa Theologica, trans. Fathers of the English Dominican Province, reprint ed. (Notre Dame: Ave Maria Press, 1981). Aquinas helpfully explains, “since the powers of the soul are destined for operations proper to animate beings, an operation has a special power of the soul appointed for it for the reason that it is an operation proper to an animate being” (DV, q. 22, a, 3, resp., 43). All quotations from the De Veritate, unless otherwise noted, are from the following translation: Thomas Aquinas, Truth, 3 vols., trans. Robert W. Mulligan, James V. McGlynn, and R. W. Schmidt, reprint ed. (Indianapolis: Hackett, 1994).

[13] ST I, q. 78, a. 4, resp.

[14] ST I, q. 77, a. 1, resp., ad 4; Questions on the Soul, q. 12, ad 10, p. 160.

[15] ST I, q. 77, a. 3, resp. In his Disputed Questions on Truth, Aquinas suggests, “inasmuch as to be moved is made an action proper to animate beings in the sense that they move themselves to definite species of movement, there is found in animals a hierarchy of special powers” (DV, q. 22, a, 3, resp. 44). He continues by providing the examples of locomotive power and vegetative powers and then discusses the appetitive powers.

[16] ST I, q. 77, a. 3, resp.

[17] DV, q. 22, a. 3, resp.

[18] DV, q. 22, a. 3, resp. Here Aquinas says, “To tend, which is in a way common to all things, likewise becomes in a way special for animate beings, or rather animals, inasmuch as there are found in them appetite and what moves the appetite. This latter, according to the Philosopher, is the apprehended good itself.”

[19] DV, q. 22, a. 12, resp.

[20] ST I, q. 83, a. 2, resp.; ST I-II, q. 49, a. 1, a. 2.

[21] ST I, q. 83, a. 2, ad 2.

[22] This definition is not only found in Aristotle, and major theologians in the Christian tradition (such as Augustine and Boethius), but Calvin also clearly agrees with this definition of man (cf. Institutes 1.15.3, p. 107.).

[23] Another way of saying this is to say that all of the faculties or powers are informed in the way that they bring about their proper acts, by reason. This includes not only the appetitive and intellectual powers, but also the vegetative power and even our use of the sensitive and locomotive powers.

[24] Or as the result of a habit (which is the result of many actions of a similar type, in similar situations, repeated).

[25] ST IaIIae, q. 1, a. 1.

[26] ST IaIIae, q. 1, a. 1.

[27] ST IaIIae, q. 1, a. 1. Aquinas adds a distinction: “an action is voluntary in one of two ways: first, because it is commanded by the will … secondly, because it is elicited by the will, for instance the very act of willing.”

[28] ST IaIIae, q. 7a, a. 1, a. 6; q. 72, a. 2; q. 74, a. 1, a. 3; q. 75, a. 1. In other places, Aquinas unpacks this two-word definition. He says, for example, that “sin is nothing else than a bad human act,” and “a human act is evil through lacking conformity with its due measure” (ST IaIIae, 71, a 6). What is this “due measure”? The two rules of the human will: (1) the proximate and homogenous will—human reason, and (2) the first rule—eternal law (cf. ST IaIIae, q. 74, a. 7, resp.). This allows us to point out two elements in the definition of sin: the matter of sin—sin is related to the substance of a human act—word, deed, and desire; and the form of sin—sin is related to the nature of evil—it is contrary to the eternal law. This basic definition is accepted by many Reformed theologians, including Berkhof (Systematic Theology, 230–33) and Charles Hodge, Systematic Theology, reprint ed. (Peabody, MA: Hendrickson, 2003), 2:187–88.

[29] ST IaIIae, q. 71, a. 5.

[30] I may not know (be conscious of the fact) that my action has broken the divine law, but if I voluntarily committed the sinful action, I have broken the divine law and, therefore, sinned.

[31] ST IaIIae, q. 71, a. 5.

[32] ST IaIIae, q. 71, a. 5.

[33] Aquinas provides us with a specific example that appears to have been as common in the Middle Ages as it is today: failing to attend corporate worship in church. One may decide to mow one’s lawn or attend a game on Sunday morning, knowing full well that by doing so it will be impossible to attend church (a greater good that one has culpably failed to do). In example 2, one stays up late partying on Saturday night knowing full well that by staying up so late it will be impossible to attend church on Sunday morning. In this case, when one sleeps through the Sunday morning service, it is not a voluntary action on Sunday morning that is the cause of the sin of omission, but a voluntary action on Saturday night whose consequence was the sin of omission on Sunday morning.

[34] Indeed, Aquinas notes (in ST IaIIae, q. 72, a. 7) that sins can be distinguished into sins of thought, words, and deed (as three types of one species). Aquinas notes, for example, (1) sin, before it is consummated, begins in the mind (sins of thought); (2) man also sins in word by declaring sinful thoughts; and (3) the deed, the sinful act, is the consummation of the act. We could add, using Aquinas’s own concepts, that even if there is no “external” action, if there is a voluntary interior act that is inordinate (whether it terminates in an exterior act or in the omission of an exterior act), then a sin has been committed (i.e., dwelling on a sinful thought).

[35] If, in my sleep, I roll over and hit my wife in the face, I am not guilty of “beating my wife.” In fact, even if a person is not sleeping, it may be possible to non-culpably strike a person. My wife and I continue to laugh about the night when, adjusting her sleep-mask, her hand slipped, and she punched me (peacefully sleeping) in the nose. She did not intend to hit me. Thus, though it is wrong to hit an innocent person, it is not always a sin to hit an innocent person.

[36] A somewhat simplistic but illuminating way of illustrating this point is to word it in relation to rust. The point of this question is, “in what is rust found?” Rust is something which, by nature, depends upon some other being for its very existence—it is found in something.

[37] ST IaIIae, q. 74, a. 1. This claim points both to those faculties which, tending towards an object, terminate in an action and to the will, which moves the person, through their faculties, to their proper end.

[38] ST IaIIae, q. 74, a. 1.

[39] Calvin also agrees with the notion that man’s higher faculties are intellect and will and that there is an interaction between intellect and will. He describes the purpose of the intellect in relation to action as “to distinguish between objects, according as they seem deserving of being approved or disapproved” (Institutes, 1.15.7, p. 110). Another way of putting this would be that the intellect presents things to the will as things to be pursued as good or rejected as evil. The purpose of the will, according to Calvin, is “to choose and follow what the intellect declares to be good, to reject and shun what it declares to be bad” (Institutes, 1.15.7, p. 111). Or, to move the person to obtain the good and avoid bad. He here mentions the subtleties of Aristotle but prefers to keep his explanation as simple as possible, describing the intellect as “the guide and ruler of the soul” and the will as following its lead, waiting for its decision (Institutes, 1.15.7, p. 111). The intellect distinguishes between good and evil and presents this to the will; the will chooses and moves to action. In this description, though not as in-depth as Aquinas, there is general agreement.

[40] In De Veritate, q. 22, a. 12, resp., for example, Aquinas argues, (1) “The reason for acting is the form of the agent by which it acts. It must accordingly be in the agent for it to act.” (2) “It is in the agent by way of an intention, for the end is prior in intention but posterior in being.” (3) “Thus the end pre-exists in the mover in a proper sense intellectually … and not according to its real existence.” (4) “Hence the intellect moves the will in the way in which an end is said to move—by conceiving beforehand the reason for acting and proposing it to the will.”

[41] DV, q. 22, a. 12, resp.

[42] It is worth considering how the will, as corrupt, may move the intellect (also corrupt) to pursue (even to take pleasure in) error/falsity, to recognize as true what is clearly false, to ignore certain truths, etc. (because of some good which is, falsely, perceived as higher). Such an act, if indulged in repeatedly, would become, according to Aquinas, a habit (vice) of mind—such that the intellect (created to love truth by nature) loves and rejoices in a lie.

[43] Aquinas proves this in the following manner: (1) “Whatever is a principle of a voluntary act is a subject of sin,” and (2) “voluntary acts are not only those which are elicited by the will, but also those which are commanded by the will” (ST IaIIae, q. 74, a. 2). The notion of “elicited by the will” refers to the proper act of the will—to will, wish, or desire x. The notion of being “commanded by the will” refers to any actions executed by another faculty as put to its execution by the will (i.e., to walk, speak, seek to know, etc.), or to not do some action (ST IaIIae, q. 6, a. 3. Cf. ST IaIIae, q. 1, a. 1, ad 2; q. 1, a. 2, resp.; q. 6, a. 4, resp.). (3) “Therefore not only the will can be a subject of sin, but also all those powers which can be moved to their acts or restrained from their acts, by the will” (ST IaIIae, q. 74, a. 2, resp.).

[44] Sense and Sensuality (the sensual appetites: irascible and concupiscent): ST IaIIae, q. 74, aa. 3–4; q. 78, a. 1. Reason: ST IaIIae, q. 74, aa. 5–6. Higher and Lower Reason: ST IaIIae, q. 74, aa. 7–10; DV, q. 15, a. 3, resp.

[45] ST IaIIae, q. 74, a. 3.

[46] ST IaIIae, q. 74, a. 5.

[47] ST IaIIae, q. 74, a. 7.

[48] ST IaIIae, q. 74, a. 7, ad 1.

[49] ST IaIIae, q. 74, a. 7, resp.

[50] ST IaIIae, q. 81, a. 1, sed contra.

[51] He argues that as all men share one common nature inherited through Adam, “all men born of Adam may be considered as one man” (ST IaIIae, q. 81, a. 1, resp.). Therefore, in Adam, all fell. Aquinas provides the example of an “association” of men. In any true association, all the members may be considered as one under the name of their association.

[52] ST IaIIae, q. 81, a. 1, resp., ad 1, ad 2; q. 81, a. 2, ad 3; q. 81, a 2, resp.; q. 81, a. 4, resp. That is, by generation. This is what is often called traducianism. This is summarized well by Millard J. Erickson: “we were present in germinal or seminal form in our ancestors; in a very real sense, we were there in Adam. His action was not merely that of one isolated individual, but of the entire human race” (Millard J. Erickson, Christian Theology, 2nd ed. [Grand Rapids, MI: Baker Books, 1998], 652).

[53] ST IaIIae, q. 81, a. 1, ad 1, ad 2. We could consider this other example provided by Aquinas: “thus a man may from his birth be under a family disgrace, on account of a crime committed by one of his forebears” (ST IaIIae, q. 81, a. 1, ad 5). There is some debate in Reformed theology on how original sin is inherited, and those debates affect our understanding of guilt. The debates turn around either a federal or natural headship approach to our relationship to Adam. Berkhof’s discussion of original guilt is helpful (Berkhof, Systematic Theology, 245–46), and it would be interesting to see whether it would be in agreement with Aquinas’s view of the guilt transmitted from original sin.

[54] ST IaIIae, q. 81, a. 1, ad 2. The Westminster divines appear to have agreed with Aquinas on this point, as they state, in chapter 6, section 3, “They being the root of all mankind, the guilt of this sin was imputed, and the same death in sin and corrupted nature, conveyed to all their posterity descending from them by ordinary generation” (Dixhoorn, Confessing the Faith, 87).

[55] ST IaIIae, q. 81, a. 3, resp.

[56] ST IaIIae, q. 81, a. 2, ad 3. Aquinas discusses the corruption of the human nature helpfully in his exposition of Romans 7:14.

[57] ST IaIIae, q. 81, a. 2, resp.

[58] ST IaIIae, q. 81, a. 2. Some might take exception with Aquinas’s description of original sin as an inherited stain, or a corruption of the human nature, but, even here, Calvin is in full agreement with Aquinas both in terminology and in doctrine. A couple of examples will suffice to prove this point. First, in discussing the image of God in man, Calvin says, “Wherefore, although we grant that the image of God was not utterly effaced and destroyed in him, it was, however, so corrupted, that anything which remains is fearful deformity” (Institutes, 1.15.4, p. 107). Later, he describes the posterity of Adam with the following words, “who, deriving their origin from him after he was corrupted, received a hereditary taint” (Institutes, 1.15.8, p. 111).

[59] ST IaIIae, q. 81, a. 2, resp.; a. 5, ad 2.

[60] In ST I, q. 95, a. 1, resp., Aquinas explains that God bestows upon man at creation, not by nature but as a divine grace, a primitive state of rectitude in which man’s “reason being subject to God, the lower powers to reason, and the body to the soul: and the first subjection was the cause of both the second and the third; since while reason was subject to God, the lower powers remained subject to reason, as Augustine says.” Put more succinctly, primitive rectitude or justice is the perfect submission of the human faculties, and in fact the entire concrete human, to the rule of reason, and reason to the divine will. With this claim, the Reformed, in general, agree (cf. Calvin, Institutes, 1.15.3–8; Berkhof, Systematic Theology, 207–9; Francis Turretin, Institutes of Elenctic Theology, ed. James T. Dennison Jr., trans. George Musgrave Giger [Phillipsburg, NJ: P&R Publishing, 1992], 1:466). Some Reformed writers either equate original righteousness with the image of God in man or see it as a part of the image of God in man (cf. Turretin, Institutes, 1:466; Berkhof, Systematic Theology, 226).

[61] ST IaIIae, q. 82, a. 2, resp.

[62] This claim (that original righteousness is bestowed on man as a grace that God gives him at creation, and not as a part, or perhaps consequence, of his nature thus created) is the specific issue on which many Reformed scholars disagree with Aquinas (arguing that it is a part or a consequence of the goodness of the human nature as created), and some have even made it the locus of their claim that Aquinas’s approach to original sin does not adequately (or at all) deal with the noetic effects of sin (cf. Hodge, Systematic Theology, 2: 103, where he states that in relation to the subject of original justice, the only point of contention between the Reformed and Catholics is the question of how it was bestowed—by nature or by grace). His portrayal of the Catholic position is not fully accurate, but his claim about the one area of contention is. Another article would be required to adequately deal with this disagreement.

[63] It is worth noting that though the nature of the “endowment of original justice (natural or by grace)” is debated, and a point of difference between some of the Reformed and Aquinas, the fact of the privation of original justice, and the consequences of that privation is a point on which the Reformed agree fully with Aquinas. (Cf. Calvin, Institutes, 1.15.4, 7; Van Dixhoorn, Confessing the Faith, 83; Berkhof, Systematic Theology, 246; Hodge, Systematic Theology, 2:227, 230–31.)

[64] ST IaIIae, q. 82, a. 3, resp. Calvin appears to agree with this point as well (cf. Institutes, 1.15.8, p. 111).

[65] ST IaIIae, q. 82, a. 1, ad 2.

[66] ST IaIIae, q. 82, a. 2, ad 3.

[67] ST IaIIae, q. 82, a. 4, sed contra.

[68] ST IaIIae, q. 82, a. 3, resp.

[69] ST IaIIae, q. 82, a. 1, resp.

[70] ST IaIIae, q. 82, a. 1, resp.

[71] ST IaIIae, q. 82, a. 2, ad 1. Again, the Westminster divines appear to agree with Aquinas here, as they state, in the Westminster Confession, ch. 6, a. 4: “From this original corruption … do proceed all actual transgressions” (Van Dixhoorn, Confessing the Faith, 87).

[72] ST IaIIae, q. 82, a. 2, ad 3.

[73] John Calvin would be in fundamental agreement with this statement. Calvin describes the words of Paul, “Indeed, he had a little before drawn a picture of human nature, which shows that there is no part in which it is not perverted and corrupted” (Institutes, 2.3.1, p. 178). After having explained that human nature is depraved and having enumerated a number of consequences of the fall, he states, “I confess, indeed, that all these iniquities do not break out in every individual” (Institutes, 2.3.2, p. 179). Berkhof also notes how sin has affected the proper functioning of each of the faculties (Berkhof, Systematic Theology, 223), describing the primary effect of original sin as follows: “the total depravity of human nature. The contagion of his sin at once spread through the entire man, leaving no part of his nature untouched, but vitiating every power and faculty of body and soul…. Total depravity here does not mean that human nature was at once as thoroughly depraved as it could possibly become” (Berkhof, Systematic Theology, 226). K. Scott Oliphint appears to agree with Aquinas on this point: “But our faculties no longer function that way [enjoying the presence of God, serving him, and worshipping him]. They have been damaged, fractured, broken, impeded, hindered, hampered, thwarted from doing what they were designed to do, since the effects of sin have enslaved and influenced them” (“The Old-New Reformed Epistemology,” in K. Scott Oliphint and Lane G. Tipton, eds., Revelation and Reason: New Essays in Reformed Apologetics [Phillipsburg, NJ: P&R Publishing, 2007], 212). It would seem that Van Til agrees with Aquinas on this point: “Sin involved every aspect of man’s personality” (Van Til, The Defense of the Faith, 70). Or, later, “On the other hand, according to Calvin, there is no ‘disturbance’ in the nature of man as he comes forth from the hands of God. The ‘disturbance’ has come in as a result of sin. Accordingly, every one of fallen man’s functions operates wrongly. The set of the whole human personality has changed” (Van Til, The Defense of the Faith, 97).

[74] ST IaIIae, q. 82, a. 4.

[75] ST IaIIae, q. 83, a. 1. He does this by first distinguishing between two ways in which one thing can be said to be in another: (1) as an effect is in its cause—principle or instrumental; or (2) as an accident is in a subject. We can say, according to Aquinas, that original sin was in Adam as its principal cause and in the semen (thus part of our flesh) as in an instrumental cause—transmitting the corrupted human nature to all of Adam’s descendants. However, in the second sense (as an accident in a subject), original sin is not in the body for the body shares in sin only as an instrumental cause (at best). Rather, suggests Aquinas, the body shares only in the consequences of sin, not the guilt, but the punishment, of sin.

[76] ST IaIIae, q. 83, a. 2.

[77] Reminder: The intellect precedes the will by proposing its object to it, but the will precedes the intellect in the order of action (even moving the intellect to act). Sin, as has already been determined, is by nature an inordinate act. Thus, if we consider original sin in relation to action, the subject of original sin must be primarily what moves man to act—the will.

[78] “Original sin, in so far as it inclines to actual sins, belongs chiefly to the will” (ST IaIIae, q. 83, a. 4, ad 1).

[79] We have also shown, contra R. J. Snell, that Aquinas’s approach to human nature and sin is not in need of augmentation by, modification by, or even transposition of Aquinas’s views into Lonergan’s introspective phenomenology. Snell thought such a transposition is necessary for two reasons: (1) Aquinas’s faculty psychology so divides man up into little parts that the unity of human nature and experience is fractured, and (2) it therefore neglects the concrete, factical, human being in favour of an abstraction.