Below is a talk I recently gave at a local apologetics meet-up. The goal was to introduce and partially defend natural law theory to a group of fellow-Protestants who, as far as I was aware, had not engaged extensively with natural law theory before. The talk was recorded in various parts, with video coming in the second part. At the end there is a collection of resources for those interested in some further reading.
In our previous meeting I got the impression that my views on morality as an Aristotelian and Thomist are particularly different from the views of many of you here, as well as Protestants more generally these days. I have two goals here tonight. The first is to introduce and partially defend the views I’ve come to hold on these issues, and the second is to explain how these relate particularly to Protestant approaches to Scripture and modern uses of the moral argument for God’s existence.
We’ll be concerning ourselves primarily with issues of meta-ethics, which is that subfield of ethics that concerns itself with (1) what we mean by certain terms like “good”, “moral”, “virtue”, “justice”, “ought”, as well as (2) how such things are grounded, by which we mean giving an account of what makes things good, moral, virtuous, etc. There are roughly two meta-ethical theories I want to talk about:
- Divine command theory, which I imagine is the view many of us here hold.
- Natural law theory, which is the view I want to recommend as best.
Now, before we start I should note that these two theories have very different approaches in terms of how they are developed. Like most modern meta-ethical theories, the divine command theory we’ll be talking about takes the term “moral” as picking out some special or mysterious class of facts that need to be defined and grounded by the theory. On the other hand, for the classical natural law theory we’ll be talking about, the term “moral” doesn’t pick out any particularly special, and is defined before we even start the theory. The focus of natural law theory is instead the notion of “goodness”.
This is noteworthy because we’re going to use the word “moral” in both senses tonight, and it can get confusing unless you keep this difference in mind.
1. Essentialist Divine Command Theory
I imagine the divine command theory that is most commonly held here is the so-called essentialist divine command theory defended by people like William Lane Craig and Robert Adams. We can sketch the rough outlines of the theory in about 7 points:
- “Moral” picks out those fact which are most fundamental and important. If our government commands us to do something immoral, for example, we still have a duty to refrain from listening to them, since our moral duties are more important than our duties to our government.
- We divide moral facts into moral values and moral duties. Moral value refers to the worth or goodness of something. Moral duties refer to the moral obligations or prohibitions that apply to us, what we ought and ought not do, rights and wrongs.
- Moral value is ultimately grounded in God’s nature or essence, in the sense that he is the paradigm of moral goodness. Because God is a person, persons are morally valuable. Because God is loving, love is morally good. And so on.
- Moral duties are grounded in God’s commands to us, which are given explicitly through revelation or implicitly through conscience. The idea here is that in general duties arise from commands from qualified authorities. For example, when a policeman commands me to do something I have a legal duty to do that, since policemen are qualified legal authorities. God, being the paradigm of moral goodness, is uniquely qualified to be a perfect moral authority, and so his commands constitute moral duties.
- God’s commands, and therefore our duties, are not arbitrary because they are based on God’s unchanging nature, which we said in (3) is the paradigm of moral goodness. Nor are they based on something external or “bigger” than him because his nature is something internal to him.
- Moral virtues are those habits that dispose us to doing good and right things as they are grounded in God’s nature and commands.
- Because moral duties arise from God in this way, it seems that so must our personal motivations for obeying them. In a Christian context this would mean that the reason we follow God’s commands is out (1) love for God and desire to be with him, and (2) fear of just punishment.
2. Thomistic Natural Law Theory
We move now to natural law theory. The particular brand of natural law that I’m interested in here is the one from by Thomas Aquinas, who himself was developing the natural law theory of Aristotle.
2.1. Morality is about practical reason
Now, as I said, as a classical theory we have the term “moral” defined upfront: “moral” picks out things relating to the will, and therefore also our actions. For example, classically we can by divide reason into speculative reason and practical reason. Speculative reason relates to our intellect and has to do with applying reason to further expand our understanding of reality. The habits that lead to good speculative reasoning are called the intellectual virtues. Practical reason relates to our will and has to do with applying reason to govern how we will and act. So habits that lead to good practical reasoning are called moral virtues.
So, while we might have inherited the word “moral” from Aristotle, it no longer has the same meaning. Classically, it did not denote some special or fundamental class of value of duty, it wasnot connected with the will of God in such a way that he could be said to be a lawgiver, and it does not carry the psychological weight of being bound by some law. In his Ethics Aristotle discusses both moral and intellectual virtues, with neither being more important than the other. The reason for this is that both moral and intellectual virtues part of being a good human.
As we said, the best starting point would be how classical natural law understands the notion of “goodness”.
2.2. Good has the nature of an end
Aquinas said that in general the good “has the nature of an end” and we’ll use this as our starting point. In a way, though, our modern ears aren’t prepared for this definition, because we’ve been taught to think of conscious deliberation whenever we think of something working for an end. But for Aristotle and Aquinas our consciousness is just a special case of the goal-directedness that exists throughout nature. For them, everything that exists has tendencies toward certain ends determined by its nature.
The thought is roughly as follows: at every level things exhibit certain natural regularities or tendencies toward certain effects. We see this in living things, like how hearts regularly pump blood, or how dogs regularly grow up to have four legs so they can walk, or how seeds regularly grow into trees. We also see this in non-living things, like how matches tend to combust when struck, the moon tends to orbit the earth, salt regularly dissolves in water, rocks regularly fall to the ground, and so on. In each case we have something consistently producing its specific effect unless its prevented from doing so in some way.
And notice that each regularity involves the production a specific effect rather than something else or nothing at all. Matches produce fire as opposed to producing ice or nothing at all. Seeds grow into trees and not into rocks. Salt dissolves as opposed to combusting. Rocks fall as opposed to exploding. And the same goes for all the numerous regularities that exist throughout the universe. But, that things consistently work to produce their specific effects seems to make sense only if “there is something in them that is directed at or points to specifically those outcomes rather than any others”.
So, in some broad sense hearts are directed at pumping blood, the development process of dogs works to produce an organism that walks on four legs, matches are directed at combusting when struck, salt is directed to dissolving in water, and so on. At the end of the day we find that everything that exhibits some form of natural regularity must be directed by its nature towards that behaviour as kind of end or goal. This is the kind of “teleology” that Aristotle and Aquinas have in mind when they talk about goal-directedness in nature, which by-and-large isn’t due to the conscious deliberation of the things themselves. Of course, working this out completely requires a fairly lengthy side-track into metaphysics and philosophy of nature, but hopefully the examples I gave will give you enough of an intuition.
Now, let’s go back to what Aquinas was saying about good having the nature of an end. What he’s getting at is that whenever we talk about an end we can also talk about goodness: something is good to the extent it fulfills its end and bad or defective to the extent that it fails to fulfill its end. If I’m playing a sports match, for instance, then my actions are good for me to the extent that they help me win the game. On the other hand, losing the game would be bad for me, and could happen because I played badly or because my opponent played better than me. A chair is good to the extent that it realizes the carpenter’s end of making something that holds people up and doesn’t fall over. And a music performance is good the extent that it achieves the orchestra’s end of playing the piece.
2.3. Natural goodness
So we have that (1) everything is in some sense directed toward certain ends by their nature and (2) whenever somethings works for an end we have a measure of goodness for that thing. This gives us a very general sense of goodness that applies to almost everything. Because this notion of goodness is so closely linked with the natures of things we can call it “natural goodness”.
It might sound odd, but this natural goodness is in some sense both relative and objective. It is relative because what is good for you is dependent on the kind of thing that you are. If you had had a different nature, then different things would be good for you. It’s bad for cats to have two legs, but it is good for humans to have two legs. A good match causes fire when used, and a good fire extinguisher stops fire when used. However it’s still objective because at the more fundamental levels you don’t decide your own nature, and cannot change it.
Now, this natural goodness serves as the springboard for all ethical reasoning in natural law theory. The basic idea is that because we can study our human nature through various empirical methods and philosophical reasoning, we can also come to a better understanding on how to live well as humans.
2.4. Accountability, duty, and authority
While we can’t go through all the details here, what I would like to do is give you a rough idea of how on natural law theory we can move from this natural goodness to thinks like moral accountability, duties, and authority.
Accountability, it seems to me, is ambiguous between two things, which we’ll take in turn: responsibility and punishment. We noted earlier that moral virtues are a special case of virtues in general, and I think something similar happens when you consider moral responsibility and responsibility in general. In general, being responsible for an action means that that action was up to you. And people typically that one’s responsibility is in some way proportional to one’s knowledge, or at least one’s capacity for knowledge. The idea here is that an action is up to you only to the extent that you understand what you’re doing. So we generally hold adults more responsible for their actions than children, who we hold more responsible for their actions than our pets, who we hold more responsible for their actions than this or that rock.
Now, humans have been traditionally been called rational animals. We don’t mean by this that humans are always perfectly rational: they’re not. Roughly, what makes animals rational is their ability to grasp and be conscious of universal concepts that particular things fall under. So there’s the particular human called Socrates, and there’s the universal concept of humanness which Socrates, Plato, and all other humans fall under. All animals are conscious in some way of particular things, but rational are those animals which are also conscious universal concepts. Now, this ability to understand universal concepts means we have the ability to understand the natural goodness and evil, that we were talking about earlier, both for ourselves and for others, as well as the ability to choose to pursue or avoid this goodness. This additional understanding about our actions results in us being held more responsible for them, and this additional layer or responsibility is what we mean by “moral” responsibility. At the end of the day, we say that an action is morally good or evil to the extent that the end or means willed in that action are naturally good or evil.
For example, if due to genetic defect or accident I have only one leg this is bad for me but I am not responsible it. In this case we have a natural evil without a moral evil. On the other hand, if I cut my own leg off then this is an evil for which I am responsible. In this case we have a natural evil with a moral dimension, since the natural evil is the product of my will.
As for punishment, one way it arises is as follows: humans are not merely rational animals but also political animals, by which we mean that it is natural and good for us to be part of various communities like families, sports teams, companies, friendships, and states. When a part is a detriment to the good of the whole, it is good for that part to be removed from that whole or to otherwise incur some debt so as to restore the good of the whole.[5, 6] For example, if my hand has gangrene it is good for me to cut it off. This removal or debt will be punishment, and if properly administered it will have to be done according to the principle of retributive justice.
What about duties? On divine command theory we have divine legal duties which arise from God’s commands to us. And although it’s not as big a focus in natural law, we can also say something about duties. We’ve seen that our nature sets certain ends for us, and to the extent that an action contributes to our fulfillment of these ends it is good. This gives us the fact that, if I will the good, then I ought act so as to fulfill my natural ends. But if we think about it, in general we act for something because we will it, and we will it because it seems good to us in some way. “The mugger who admits that robbery is evil nevertheless takes his victim’s wallet because he thinks it would be good to have money to pay for his drugs.” What this means, however, is that we always will what seems good to us, even if sometimes we incorrectly prioritize some goods over others. Combining this with our earlier fact we get to the following conclusion:
- If I will the good, then I ought act so as to fulfill my natural ends.
- I do will the good.
- Therefore, I ought act so as to fulfill my natural ends.
After some reflection on our natures this will result in various duties such as “I ought not steal”, “I ought not murder”, “I ought honor my parents”, and so on. But what kind of duty is this? It’s certainly not a legal duty that we get from divine command theory, since it doesn’t arise from any command. We might call it a rational or a natural duty since it arises out of our natural capacity for practical reason. It serves to show us that we should be interested in what is naturally good for us.
And finally, what of authority? Here we combine some of the points we’ve already made. The idea here is that someone has authority over me if they are in charge of my good, since I ought seek my good, and therefore I ought listen to their commands. Different people will have authority over different areas of my life and to different degrees depending on their position and qualification, and in each case something like this idea applies.
2.5. The four laws
Now, is there any place for a divine legislator on natural law theory? This is one of the main areas where Aristotle and Aquinas differ. For Aristotle, God is not a divine legislator and the only place he takes in the ethics is as the object of our highest end which is philosophical contemplation about him. Aquinas, however, thinks Aristotle made a mistake here. In unpacking what he thinks is the correct view, Aquinas explains that there are ultimately four kinds of law:
- There’s the eternal law, which embodies God’s knowledge of all the various natures of things he could have created, and so what would have been good for them.
- There’s the natural law, which is what we’ve been speaking about here. For humans this forms the foundation for all our practical reasoning. It tells us what it means to act well as the kinds of things that we are. It’s called “natural” law because all of this derives from our natures.
- There’s human law, which are laws promulgated by a human legislator in charge of a community. Natural law is often very vague and general and it’s application in particular cases requires careful consideration by wise people. “[H]uman law is essential for living the good life because it makes the general precepts of the natural law more specific.” Human law is authoritative because it’s based on natural law.
- Finally there’s the divine law, which are laws promulgated by God, the divine legislator. This law most closely represents that law that we think of in divine command theory, and they are the laws that are proclaimed through some form of revelation.
So there is a place for divine law, but it’s embedded in this bigger theory of ethics. Ultimately I think every intuition we have explained in divine command theory can be relocated somewhere in natural law theory, with a richer foundation, since natural law gives us accounts of things like authority, responsibility, and so on.
3. Modern Protestant objections
So with that overview of natural law theory, let’s talk briefly about it means for Protestantism. I think a lot of Protestants these days are quite resistant to the idea that moral prescriptions or substantial moral knowledge might come from somewhere outside of scripture. I say “these days”, because neither the church historically nor the reformers themselves had a problem with natural law theory. John Calvin, for example, said the following in his Institutes:
It is a fact that the law of God which we call the moral law is nothing else than a testimony of the natural law and of that conscience which God has engraved upon the minds of men.
I think our modern hesitance arises from a combination of two things. On the one hand there’s been an increasing loss of acquaintance with natural law thinking in the past few hundred years, because of what I take to be certain philosophical errors of the early moderns like Descartes and Locke. Recently we’ve started correcting these errors, but our culture as a whole has lost its grip on this kind of thinking. And when we consider certain doctrines like original sin and sola scriptura against this backdrop they might seem to be at odds with what I’ve been saying.
So consider original sin, which says that our natures have been disordered, which in turn undermines our ability for unaided reason and therefore the moral conclusions we draw from it. But there’s nothing in this that contradicts what I’ve been saying. The claim that we can come to know ethical truths through philosophical reflection does not require that we be infallible in our conclusions. All that follows from our fallibility is that our understanding of ourselves, like our understanding of any part of nature, needs to be a community effort that spans many generations and societies. And the same thing can be said of our understanding of scripture itself. To quote John Goyette:
The collective effort required for the development of the arts and sciences is, for Aquinas, one of the reasons why man is a political animal. But the same is true of human law: it a collective effort requiring experience and time, and the wisdom of the wise. Just as men perfect the arts and sciences as part of a community, so do men perfect their knowledge of the natural moral law by participating in the [political community].
What about the doctrine of sola scriptura, or “scripture alone”? There seem to be a number of slightly different of ways of formulating the doctrine,  but if it’s to be consistent with scripture it can’t claim that scripture is the only source of moral knowledge, for two reasons. First, because scripture itself references other sources like conscience. One of the clearest places where we see this is in Paul’s letter to the Romans where he talks about the Gentiles and he says that even though they haven’t been given the law through revelation, “they show that the requirements of the law are written on their hearts, their consciences also bearing witness.”
The second reason is because scripture must presuppose some knowledge of the world, and this knowledge includes some things pertaining to morality. J. Budziszewski gives the following example:
Consider for example the prologue to the Ten Commandments, where God reminds the Hebrew people of their indebtedness to Him: “And God spoke all these words, saying, ‘I am the LORD your God, who brought you out of the land of Egypt, out of the house of bondage. You shall have no other gods before me ….'” How is it that the people of Israel, before the proclamation of the law, already know the law of gratitude? The answer is that the basics of natural law are already impressed upon the innermost design of the created moral intellect. We know a part of God’s will for us even before receiving it in words.
3.1. The role scripture
I suppose we might wonder what does scripture adds if we can to know moral conclusions apart from it. There are a number of things we can say here.
- In general there are things about God and ourselves that we can’t know through unaided reason and scripture is needed for these. Things like God’s triune nature or his dealings in human history, particularly what we call redemptive history, what will happen after we die, that marriage is a symbol for Christ and the church, and so on.
- Because of God’s revelation to us through scripture and through Jesus we are able know God personally, which wouldn’t be possible otherwise, since friendship requires communication between friends. As Jesus says in John’s gospel, “No longer do I call you servants, for the servant does not know what his master is doing; but I have called you friends, for all that I have heard from my Father I have made known to you.”
- Revelation of God’s commands serves to introduce divine law and duties, which we wouldn’t have otherwise.
- Revelation about morality serves as a guide and summary of natural law. We’ve already seen that it can be difficult to work out the details of natural law, and besides that not everyone has the gifts or time to work them out. So through revelation God enables more people to know and will the good.
As we close I want to say a few things about what natural law means for apologetics today.
4.1. The moral argument
Like most arguments for God’s existence the “moral argument” is really a family of arguments. The one most heard today is formulated as follows:
- If God does not exist, then objective moral values and duties do not exist.
- Objective moral values and duties do exist.
- Therefore, God exists.
The question I want to address is how natural law effects the prospects for a moral argument like this.
Now, Aquinas gave arguments for God’s existence in various places throughout his writings, although most famous are the so-called “five ways” he lays out in the Summa Theologica. As far as I can tell Aquinas never gave a moral argument. I think the reason for this is that from a natural law perspective morality is not some special part of reality that calls out for an explanation, but is rather the result of the combination of otherwise non-moral features of reality: (1) the goal-directedness we see throughout nature and (2) the wills of rational beings.
The closest thing Aquinas gives to a moral argument is his fifth way, which is a teleological argument. I should note, though, that the teleology Aquinas has in mind is different from the kinds of teleology we see in modern arguments for God’s existence. He’s not concerned with the complexity of living things or the fine-tuning of the universe, for instance, but rather the goal-directedness we spoke about earlier, which is required by the various regularities that exist at all levels of nature both complex and simple.
Now, the question arises of how something can be directed toward and end. It’s clear how this happens with intelligent beings, since there the end in some sense existing in the intellect of that being, and so it can guide the actions of that being. But with non-intelligent things, since they lack an intellect, their ends can’t influence them in the same way. So it seems that non-intelligent things must be directed toward their ends by something with intelligence. And in fact, we could see why this is the case if we spent some time analyzing the notion of intelligence, but we don’t have time for that now. This is how Aquinas summarizes what we’ve been saying in his fifth way:
Now whatever lacks intelligence cannot tend towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exits by whom all natural things are directed to their end; and this being we call God.
Of course there is still lots to be unpacked. After he gives his five ways, Aquinas spends some time explaining why this is the being we call God. He argues for God’s oneness, goodness, omnipotence, omniscience, simplicity, eternity, and a host of other divine attributes, but we just don’t have time to give and defend those arguments now.
Coming back to the moral argument. I think technically we can still use it as I formulated it, but we must recognise that it is partly dependent upon something like the fifth way for its soundness. At the end of the day I think much moral debate can be had without reference to God, since it is based on what is knowable about our nature. But ultimately I think any viable ethics depends on God, including natural law.
4.2. Cultural apologetics
Finally, from the perspective of cultural apologetics natural law serves as a common ground for Christians and non-Christians to discuss ethical issues, since particular moral conclusions do not depend on whether one thinks God exists or not. For example, atheist philosopher Phillipa Foot has said that,
… the Summa Theologica is one of the best sources we have for moral philosophy, and moreover that St. Thomas’s ethical writings are as useful to the atheist as to the Catholic or other Christian believer.
In the Western world it’s becoming increasingly important that we be able to defend the value of human life, and of family life, and particularly the rights of children. Our culture truly is a “culture of death”, in which people think it’s OK to kill innocent human beings so long as they’re young enough or helpless enough, and more generally in which we ignore the rights of children so that adults can do what they want. All too often these days I see people object to things like these on so-called “religious grounds” and then get ignored because the secular world doesn’t share their religious convictions. But there are good arguments wholly apart from any religious confession, and these need to be the primary go-to point for us.
A secondary point is that as we show the reasonableness of so-called “traditional” moral conclusions, we also show in part the reasonableness of the Christian worldview. In this way natural law can help show our culture that Christianity is an intellectually viable worldview, which is something they’ve forgotten amongst all the hype with the New Atheists.
For more on natural law, Feser’s blogpost Whose nature? Which law? which goes into more detail about this technical word “natural”. There’s also his article Natural Law, Natural Rights, and Private Property, which has a short introduction to natural law as well as an example application of it to property rights. If you’re interested in structure of the approach many natural law theorists take when unpacking the specifics of natural law, see my blogpost Goods, basic goods, and facultiesand David Oderberg’s paper The Structure and Content of the Good.
On the relationship between God and natural law see Edward Feser’s blogposts Natural law or supernatural law? and Does morality depend on God? While the fifth way is a sound argument for God’s existence, I tend to prefer the second way. See Edward Feser’s An Aristotelian Proof for the Existence of God for a good talk on this, as well as a taste of how we might go about arguing why we call this being God. If you’re interested in the fifth way, I recommend his paper Between Aristotle and William Paley: Aquinas’s Fifth Way.
Finally, one of the things that cam up in the question time was the notion of divine simplicity. William Lane Craig on divine simplicity is a blogpost by Edward Feser where he discusses some contemporary objections, and On Three Problems of Divine Simplicity is a paper by Alexander Pruss doing likewise.
For more, see the notes below, as well as the long list of categorised resources over at my blog.
- See, for instance, Robert Adams’s Finite and Infinite Goods. In contrast to essentialist versions of divine command theory there are the voluntarist versions like the one put forward by Ockham, which place both values and duties at God’s commands. I’ve also discussed what I call derivative divine command theory, in which duties are prior to values.
- I mean more important in the sense of needing to be studied. He thinks that the intellectual virtues are better than the moral virtues, since the highest end of man (or, to use modern terminology, man’s superordinate basic good) is philosophical contemplation of God.
- ST I-II Q9 A1 corp.
- Edward Feser, Scholastic Metaphysics.
- “Now every part is directed to the whole, as imperfect to perfect, wherefore every part is naturally for the sake of the whole. For this reason we observe that if the health of the whole body demands the excision of a member, through its being decayed or infectious to the other members, it will be both praiseworthy and advantageous to have it cut away. Now every individual person is compared to the whole community, as part to whole. Therefore if a man be dangerous and infectious to the community, on account of some sin, it is praiseworthy and advantageous that he be killed in order to safeguard the common good…” (ST II-II Q64 A2 corp)
- “… whatever rises up against an order, is put down by that order or by the principle thereof. And because sin is an inordinate act, it is evident that whoever sins, commits an offense against an order: wherefore he is put down, in consequence, by that same order, which repression is punishment.” (ST I-II Q87 A1 corp) This is a more general version of what was said in . I’ve briefly discussed this comment elsewhere.
- The argument, very briefly, is as follows: in order for the good of the whole to be best upheld, punishment ought only be of guilty people, ought be proportional to the crime, and ought be equal (ie. like punishment for like crimes). There are at most four putative theories of justice: deterrence, correction, preventative, and retributive. Only the last safeguards all three of these conditions. This is not to say that punishment couldn’t also include deterrence, correction, and prevention, but it must minimally be based on the principal of retribution. A supporting argument is that only retributive justice sees the agent as a human, and is therefore the only theory that affords them proper respect. Deterrence sees only a behaviour, correction only a patient, and prevention only a future threat.
- Edward Feser, Classical Natural Law Theory, Property Rights, and Taxation.
- Compare this argument to the following: (1) If I will to draw a straight line, then I ought use a ruler, (2) I will to draw a straight line, (3) Therefore, I ought use a ruler. (3) is consistent with me not realising that rulers are the best way of drawing straight lines. Similarly, that I will the good is consistent with me not having a perfect grasp of what that involves. And even once I realise it involves acting so as to fulfill my natural ends, I still won’t have a perfect grasp of what such fulfillment involves.
- John Goyette, On the Transcendence of the Common Good
- John Calvin, Institutes of the Christian Religion, IV. XX. 15
- This arises because we need to find a formulation that is not the Roman Catholic doctrine ofprima scriptura but at the same time doesn’t lead to self-defeat.
- Romans 2:15, New International Version.
- J. Budziszewski, Does Sola Scriptura Mean “No Natural Law”?
- I’m particularly fond of what John O’Callaghan says about the general relationship between theology and philosophy here. A noteworthy quote is: “Theology doesn’t take place in a vacuum just because it something heard from the mouth of God… and so we need to understand what’s presupposed to being able to hear what is being preached to us or what is being revealed to us, and then a systematic reflection upon it. Theology shouldn’t take place in a vacuum.”
- John 15:15, English Standard Version.
- For a lengthy and substantive defense of Aquinas’s fifth way see Edward Feser’s Between Aristotle and William Paley: Aquinas’ Fifth Way.
- See Edward Feser’s Teleology: A Shopper’s Guide.
- ST I Q2 A3 corp.
- Phillipa Foot, Virtues and Vices.