Options
Research

Morality and Relations before Hume

Author
  • Stewart Duncan

Abstract

In his Enquiry concerning the Principles of Morals, David Hume said that a group of earlier modern philosophers, beginning with Malebranche, held that morality was founded on relations. In this paper I follow up on that suggestion by investigating pre-Humean views in moral philosophy according to which morality is founded on relations. I do that by looking at the work of Nicolas Malebranche, John Locke, and Samuel Clarke. Each of them talked prominently about relations in their accounts of basic aspects of morality. Beyond that, each of them turns out to have held both metaphysical and epistemological views that might be described as founding morality on relations. Despite the definite differences between the three philosophers’ approaches, Hume does seem to have noticed a genuine connection here—even though he himself tended to ignore significant versions of this approach when criticizing it.

Keywords: Hume, Malebranche, Locke, Clarke, morality, relations

How to Cite:

Duncan, S., (2025) “Morality and Relations before Hume”, Journal of Modern Philosophy 7. doi: https://doi.org/10.25894/jmp.2444

Downloads:
Download XML
Download PDF

15 Views

3 Downloads

Published on
2025-06-17

Peer Reviewed

License

Creative Commons Attribution-NonCommercial 4.0

1. Introduction

At one point in his Enquiry concerning the Principles of Morals, David Hume mentions a “late author of genius, as well as learning” (EPM 3.34). In a note he identifies that author, Montesquieu, as

The author of L’Esprit des Loix. This illustrious writer, however, sets out with a different theory, and supposes all right to be founded on certain rapports or relations; which is a system, that, in my opinion, never will be reconciled with true philosophy. Father Malebranche, as far as I can learn, was the first that started this abstract theory of morals, which was afterwards adopted by Cudworth, Clarke, and others; and as it excludes all sentiment, and pretends to found every thing on reason, it has not wanted followers in this philosophic age.

Hume does more than just identify the “author of genius.” He attributes to Montesquieu the view that morality is “founded on … relations” and then sketches a history of that view, which runs from Malebranche through Cudworth, Clarke, and unnamed others.1 My aim in this paper is to understand what the view that morality is founded on relations was. I do this by looking at some views in pre-Humean moral philosophy—views which one might characterize, as Hume did, as founding morality on relations.

Hume connects the view that morality is founded on relations to another view: that morality is related to reason rather than sentiment. That is, in part, an epistemological view, a view about what the faculty is by which we learn about morality.2 At first sight, however, the foundation of morality on relations does not require the further view that morality is known by reason rather than sentiment. It would be helpful to understand why anyone thought the two views went together (especially as not all views that found morality on relations exclude all sentiment from the picture). More basically, it would be good to understand what the view that morality is founded on relations was supposed to be. No doubt there are moral relations: worse than, for instance. And perhaps some other moral notions inherently involve relations: parricide is so called because of the relation between the perpetrator and the victim. But what would it be to think that all morality is founded on relations?

There are many views that might be described as founding morality on relations. More limited versions might just say that some aspects of morality depend on relations—perhaps we have special obligations to our family members just because of our relations to them.3 But what I am interested in here are views according to which morality more generally and fundamentally depends on relations.4 In this paper I focus on the views of three pre-Humean authors. I begin with Nicolas Malebranche, whom Hume identifies as the originator of the view that morality is founded on relations. I then turn to someone Hume does not name in his note, but who plausibly belongs among his “others”, John Locke. Finally, I look at a notable figure of the early eighteenth century with whom Hume engaged repeatedly, Samuel Clarke.5

This is a paper about pre-Humean moral philosophy, not about Hume. Nevertheless, it will be useful to consider two issues arising from Hume’s text before looking at Malebranche et al.

First, consider Hume’s discussion in the Treatise of the view that moral distinctions are derived from reason. There, Hume mentions the view “that there are eternal fitnesses and unfitnesses of things” (Treatise 3.1.1.4). That may not appear to involve relations, but it is a reference to the views of Samuel Clarke, which put relations at the metaphysical foundation of morality. Moreover, Hume argues that if “morality is susceptible of demonstration…vice and virtue must consist in some relations; since ’tis allow’d on all hands, that no matter of fact is capable of being demonstrated” (Treatise 3.1.1.18). This connects a rationalist thought, that there can be moral demonstrations or proofs, to a view about relations, through a view about what sorts of things can be demonstrated. These two aspects of Hume’s discussion in Treatise 3.1.1—the reference to a substantive metaphysical view about fitnesses, and the connection to an epistemological view about demonstration—turn out to mirror two aspects of the little tradition that Hume constructs in his note in the moral Enquiry. Some philosophers—at least the ones I discuss in this paper—held epistemological views that implied moral knowledge must be knowledge of relations, or metaphysical views about certain relations being the bases on which morality is founded, or both.6

Second, someone might suspect that we do not need to investigate pre-Humean moral philosophy to understand the view that morality is founded on relations. Could this view not be understood just by looking at Hume’s text, using Humean terminology? We famously find in Hume’s work the notion of a relation of ideas, and the contrast between relations of ideas and matters of fact (EHU 4.1). Is the view that morality is founded on relations not simply the view that morality involves relations of ideas rather than matters of fact?

Relations of ideas are things (objects of enquiry, or propositions) that are intuitively or demonstratively certain. Mathematical knowledge involves such relations of ideas. What is it about the things known in this category that lets them be known in this way, and without enquiry into what exists outside the mind? It is that they just are relations of ideas: all there is to know, in the mathematical case, is how ideas relate to one another.7 There are for Hume no extra-mental mathematical objects or structures. Thus, to say that morality involves relations of ideas would be to say that moral truths can be known intuitively or demonstratively, that they can be known without investigating whether extra-mental objects exist, and that they depend simply on the relations between ideas.

This is related to some things we will see below, in particular to aspects of Locke’s epistemology.8 But despite the similarities, Locke’s epistemology is not Hume’s. Moreover, Locke’s account of morality and relations has other, non-epistemological aspects. In general, the view that morality is a matter of Humean relations of ideas is just one version of the view that morality depends on relations. It is plausibly a version that Hume had in mind in some of his critical discussions, but not the only one.9 When Hume addressed the view that morality was founded on relations, he was not just addressing the view that it was founded on Humean relations of ideas, but also views of Malebranche, Locke, and Clarke, which are—as we will see—significantly different from this. So even if you were just interested in understanding Hume’s critical discussion, you would need a broader understanding of the view that morality is founded on relations than you would get from reading it in Humean terms. For my goal of understanding the pre-Humean view that morality depends on relations, just thinking in terms of Humean relations of ideas will clearly not be enough.

2. Malebranche

Hume was well aware of Malebranche’s philosophy. In 1737, when he recommended to Michael Ramsey some books that might help him in reading the Treatise, the first he named was Malebranche’s Recherche de la vérité (Popkin 1964, 775). There are numerous points of connection between Hume’s philosophy and Malebranche’s. Sometimes these are explicit—the note from the second Enquiry with which I began, and a note directing readers to Malebranche’s work in Treatise 1.3.14, “Of the idea of necessary connexion”—but Hume’s engagement with Malebranche went far beyond those brief mentions.10

In this section, I first look at Malebranche’s discussion of relations of perfection. Those relations are supposed to provide a metaphysical basis for morality. I then look at some epistemological aspects of Malebranche’s discussion, which give us another reason to say that he founded morality on relations.

2.1 Malebranche: relations of perfection

In 1684 Malebranche published his Traité de morale, his treatise on ethics. The first chapter of that work lays out some basic views about the topic. Looking at it allows us to see one reason why someone might think that Malebranche founded morality on relations.

In the early sections of the chapter Malebranche tells us we can know, by reason, something of what God thinks. Section VI then tells us of two sorts of relations we can learn about. The first are relations of magnitude. Thus, we can learn mathematical truths, both arithmetic and geometrical. We can also discover relations of perfection, which are “the immutable Order which God consults when He acts, the Order which must also govern the esteem and love of all intelligent beings” (Malebranche 1993, 46).11 Here we find relations at the basis of morality.

Malebranche goes on to develop that initial notion. Thus, section VII tells us that all minds see the same relations of magnitude and perfection. I see the same ones as you, and we all see the same ones as angels and God.12 We are finite and fallible where God is not, but the relations we discover are the same ones. The morality that we can know is thus the very same morality that God knows. Malebranche emphasizes that we see the relations of both sorts—there is in some sense a perceptual model here—and that our judgment should follow that sight. Subsequent sections explore the issues of finitude and fallibility.

In section XII Malebranche gives examples of the relations of perfection that lie at the basis of morality. A man, we are told, is more perfect than a horse, which is more perfect than a stone. In addition, and because of that, a man is more estimable than a horse, which is more estimable than a stone. The things which are more perfect should be more esteemed, and indeed more loved, because of their greater perfection. This gives us a basic picture of part of morality. If I compare two beings and see that one is more perfect than the other, then I ought, Malebranche tells us, to esteem and love the more perfect one more than I do the other. This applies to God’s love as well as humans’. Thus, Malebranche explains what it means for God to be just—that “He loves his creatures in proportion as they are loveable, in proportion as they resemble him” (section XV; Malebranche 1993, 48). Meanwhile, returning to humans, the goal of proportioning love to perfection is connected to our happiness, our duty, our own perfection, and virtue (sections XVII–XX; Malebranche 1993, 49).

There is a lot one might explore in more detail here.13 But we have seen enough to recognize that Malebranche could fairly be described as having a view on which morality is founded on relations—in his case, relations of perfection.

Malebranche also gives an important role to reason. Indeed, the chapter begins, “The Reason which enlightens man is the Word or the Wisdom of God Himself. Though every creature is a particular being, the reason which enlightens man’s mind is universal” (Malebranche 1993, 45). As with the view about relations, there are many things about which one might say more here. For instance, Malebranche does not really mean the same by “reason” as Hume does. For Hume, reason is a faculty or ability of human minds.14 For Malebranche, it is common to all intelligent beings (section II), it is the good or the law of those beings (section III), and it is “the only authority higher than minds” (section VIII; Malebranche 1993, 46).

Despite these complications, it is clear that Hume was picking up on genuine parts of Malebranche’s view. For Malebranche, morality is founded on relations—namely, relations of perfection—and our knowledge of those relations involves reason. Nor is this view of Malebranche’s confined to the Traité de morale. We can also find it in Elucidation X of the Recherche de la vérité.

In Elucidation X, Malebranche argues that moral condemnation only works because there is “an order, a rule, a universal and necessary reason, that is always present to those who know how to retreat within themselves” (Malebranche 1997, 617). Continuing, he argues that in God there are “intelligible ideas or perfections” of things, through which God knows those things’ essences (Malebranche 1997, 617). Truths, then, are “relations of equality or inequality between these intelligible beings” (Malebranche 1997, 617). Thus, Malebranche says, truths “as well as ideas, are necessary and immutable” (Malebranche 1997, 618).

Now, “what makes a man moral is that he loves order and conforms his will to it” (Malebranche 1997, 618). The intelligible ideas vary in their degrees of perfection, and so there is an “order among them” (Malebranche 1997, 618). This order is the hierarchy of perfection. Malebranche goes on to argue “that just as there are necessary and eternal truths because there are relations of magnitude among intelligible beings, so there must also be a necessary and immutable order because of the relations of perfection among these same beings” (Malebranche 1997, 618). Here again we have the relations of perfection paired with the relations of magnitude or quantity, as in Malebranche’s moral treatise.

But how, Malebranche asks, does this give rise to obligation? It might seem simply to yield many statements of fact about a hierarchy. What he argues, once more, is that our love should be proportionate to order; that is, we ought to love things in proportion to their degree of perfection. Still, one might wonder what force that hierarchy of perfection really ought to have. Why might it not be the case that “we clearly see … that minds are more noble than bodies, but we do not see that this truth is at the same time an order that has the force of law and that we are obliged to prefer minds to bodies” (Malebranche 1997, 619)? In response, Malebranche first considers what is the case for God, namely, that “He necessarily loves His own perfections”, and consequently that he will love more perfect things more than less perfect ones (presumably because they possess more of those same perfections). Malebranche then argues that the order of perfections also has “the force of law” for humans (Malebranche 1997, 619). God “has created us in His image and likeness,” and in doing so has made us so that we can see the ordering of perfections and react appropriately to them (Malebranche 1997, 619). Those reactions to perfection might be corrupted by other aspects of our nature—concupiscence, “corruption of the heart,” or the like—but Malebranche insists that whatever effects they have, “order is always a law that is essential and without exception with regard to us” (Malebranche 1997, 619).

The fundamentals of Malebranche’s view are consistent across the Traité de morale and Elucidation X. There are relations of perfection between things (e.g., a human is more perfect than a mouse). God loves things in proportion to their perfection, and we ought to do so. The underlying relations of perfection are thereby the basis of morality.

2.2 Malebranche: epistemological aspects

Above I focused on the metaphysical aspect of Malebranche’s position, his view about what the relations are on which morality is founded. There is also an epistemological aspect. We have already seen some epistemological views, in particular a key comparison between mathematical and moral knowledge, each involving a particular sort of relation. There is also a relevant, more general aspect of Malebranche’s views in epistemology.

In Book 6 of the Recherche, after saying that “[t]ruth is nothing else but a real relation,” Malebranche tells us that:

There are three kinds of relations or truths. There are those between ideas, between things and their ideas, and between things only. It is true that twice two is four—here is a truth between ideas. It is true that the sun exists—this is a truth between a thing and its idea. It is true that the earth is larger than the moon—here is a truth that is only between things.

Of these three sorts of truths, those between ideas are eternal and immutable, and because of their immutability they are the standards for all other truths, for every standard must be invariable (Malebranche 1997, 433).15

Malebranche says that all truth consists in relations, whether between ideas, or between ideas and things, or between things. Only the first sort can be known by using “the mind alone,” that is, as Andrew Pyle (2019, 82) puts it, a priori. Knowledge of the first sort of truth will depend on the perception of a relation between ideas. These Malebranchean relations of ideas involve, of course, relations between ideas in the mind of God, in contrast to Humean relations of ideas, which involve relations between ideas in the minds of finite thinkers.

In the above passage we see just the mathematical truths, the relations of magnitude, in that first category. But given what Malebranche says elsewhere about the significant similarities between relations of magnitude and of perfection, it appears that the relations of perfection, and thus knowledge of moral truths, must belong here as well.16 Given the epistemological views I have just described, such moral knowledge will involve knowledge of moral relations.

In summary, there are both metaphysical and epistemological reasons to ascribe to Malebranche the view that morality is grounded in relations. To that extent, Hume was correct. But was he also correct to say there was a line of later thinkers who also held such views? To investigate this question, I turn my attention to Locke.

3. Locke

Malebranche and Clarke both appear on Hume’s list of those who think that morality is founded on relations. Locke does not. So why discuss him? Hume does say that the view is held by philosophers other than those he names, but why pick out Locke in particular?

Locke was a significant figure in the discussions I am talking about, and Locke’s views are an important part of the background to Clarke’s work as well as Hume’s. More specifically, the reason for including Locke lies in Essay 2.28, which is titled “Of other Relations,” but which focuses largely on moral relations (2.28.4–17). It is there that Locke explains what it is for actions to be morally good and evil. Good and evil in general have already been explained hedonistically by Locke, but moral good and evil are to be explained using moral relations. So too, indeed, are the notions of virtue and vice.

In my discussion of Locke, I first look at Essay 2.28. I then turn to epistemological aspects of Locke’s discussion that also give us reason to judge that he believed morality was founded on relations. Those epistemological aspects connect to the ways in which Locke thought morality might be known by reason.

3.1 Locke: moral relations in Essay 2.28

Good and Evil, as hath been shewn … are nothing but Pleasure or Pain, or that which occasions, or procures Pleasure or Pain to us. Morally Good and Evil then, is only the Conformity or Disagreement of our voluntary Actions to some Law, whereby Good or Evil is drawn on us, from the Will and Power of the Law-maker; which Good and Evil, Pleasure or Pain, attending our observance, or breach of the Law, by the Decree of the Law-maker, is that we call Reward and Punishment (Essay 2.28.5).

In this view, moral good and evil depend fundamentally on a relation, conformity. An action that conforms to the appropriate law is morally good, while one that fails to do so is morally bad. This much is stated by Locke without much argument. Indeed, the one hint of an argument here is the “then” that connects his view about moral good and evil to his previous hedonism about good and evil more generally. Rather than developing an argument for his view, Locke focuses on discussing what the relevant law is, which determines actions as morally good or evil.

There are, Locke says, three sorts of laws to which we might be referring, when we use this language: “1. The Divine Law. 2. The Civil Law. 3. The Law of Opinion or Reputation, if I may so call it” (Essay 2.28.7). The first of these, the divine law, is “that Law which God has set to the actions of Men, whether promoted to them by the light of Nature, or the voice of Revelation” (Essay 2.28.8). This is the correct law by which to make judgments of moral good and evil, “the only true touchstone of moral Rectitude” (Essay 2.28.8). For an action to be morally good is for it to conform to the divine law. That relation of conformity is the relation on which this aspect of Locke’s moral philosophy is founded.

For Locke the civil law, by which he means in general “the Rule set by the Commonwealth” (Essay 2.28.9), is the measure of criminality rather than moral good or evil. An action’s criminality is to be explained in the same way as an action’s evil—as its not conforming to the relevant law—but the law involved is different.

The third law, that of opinion or reputation, plays a more complex role. For although Locke thinks the divine law is the true measure of morality, he also thinks that people tend to use the law of opinion as their measure of moral goodness, rightness, and in particular, virtue. The actions that are approved of “according to the Judgment, Maxims, or Fashions” (Essay 2.28.10) of a place come to be called virtuous, and indeed right and good, because of their conformity to the law of opinion. This is not how one ought to judge moral goodness—this is not what moral goodness is—but this often is how people talk of moral goodness. 17 Even if one were to make that mistake, however, and judge actions relative to the mores of one’s society, one would still be judging them in terms of their conformity to a rule (Essay 2.28.14).

3.2 Locke: epistemological aspects

In Locke, as in Malebranche, we see more than one way in which one might attribute the relations-involving view to the author. In Malebranche, we saw both the view about relations of perfection and the epistemological view about truth and knowledge involving relations. In Locke, we have seen the view about relations to laws. Here, too, there are relevant epistemological views.

Begin here with Locke’s basic account of knowledge. Knowledge is, he says, “nothing but the perception of the connexion and agreement, or disagreement and repugnancy of any of our Ideas” (Essay 4.1.2). This applies both to intuitive knowledge, the best sort, in which we perceive that agreement or disagreement immediately, and to demonstrative knowledge, in which we perceive it using some intermediate idea(s). Locke usually talks of perceiving the agreement or disagreement of ideas, rather than the relation between them, but fundamentally his view of knowledge is that it involves seeing how two ideas relate to one another. Stepping away from Locke’s terminology, then, we can say that for him, to know is to know a relation. Locke himself reserves talk of relations for a subset of cases (Essay 4.1.3–7), but we can fairly use “relation” more broadly than Locke, if we take care not to confuse our sense of it with his. Thus, we can say that for Locke, all knowledge is knowledge of relations. Consequently, moral knowledge is knowledge of relations.18

That might not appear to be a terribly exciting or distinctive way in which to say morality involves relations, for it might seem just to be the view that moral knowledge is propositional. Locke does in general seem to think that all knowledge is propositional, so surely he thinks moral knowledge is.19 However, in Locke, as in Malebranche, the epistemological view, which implies moral knowledge must be of relations, is accompanied by a metaphysical view about what the fundamental relations are. In Malebranche, they are relations of perfection, but in Locke they are relations to laws. Thus, both Locke and Malebranche seem to be good examples of philosophers before Hume who might fairly be said to have founded morality on relations.

It is worth also noting Locke’s hope that we might have a deductive science of morality, placing “Morality amongst the Sciences capable of Demonstration” (Essay 4.3.18). This perhaps does not connect so obviously to the slogan about morality being founded on relations. But it does relate to Hume’s criticisms of the relations view as involving demonstration. For Locke, unlike Hume, thinks that there could be a demonstrative moral science, as well as demonstrative mathematical ones. In mathematics we find the commonly agreed cases of demonstrative knowledge. However, we can have demonstrations involving ideas other than those of quantity, and there is no reason in principle why we should not be able to have demonstrations involving moral ideas. There may well be practical obstacles: Locke talks, for instance, of such demonstrations as being able to “afford us Certainty, if Vices, Passions, and domineering Interests did not oppose, or menace such Endeavours” (Essay 4.3.18). But we can compare non-mathematical ideas, indeed, moral ideas, in demonstrative sequences.20 Locke gives two examples of such demonstrations: arguments for the claims that “where there is no Property, there is no Injustice” and that “No Government allows absolute Liberty”.21 Notice two important basic points. First, we have again the connection between morality and mathematics. Second, reason is playing an obvious role here, for it is reason that allows us to give demonstrations.

Locke fits nicely into the little tradition Hume constructed, even though Hume does not name him as part of it. As in the case of Malebranche, there are two reasons why one might think Locke founds morality on relations. There is a metaphysical reason: moral good and evil fundamentally involve the relation of an action to a law. And there is an epistemological reason: Locke takes moral knowledge, like all knowledge, to be the perception of a relation between ideas. Looking further at Locke’s moral epistemology, particularly at the possibility of moral demonstration, we see also a definite role for reason, as well as a familiar comparison between moral and mathematical knowledge.22 There are other aspects of Locke’s moral philosophy, and considerable questions about how the various aspects fit together. But he does clearly belong within the relationist tradition that Hume described.23

4. Clarke

Samuel Clarke may perhaps be best known now as a correspondent of Leibniz’s—and even then, Clarke is sometimes treated more as a spokesman for Newton than as a philosopher in his own right. In his own day he was, however, a significant philosophical and theological figure, writing on topics from baptism to natural philosophy. Hume engaged repeatedly with Clarke’s work.24

In the early years of the eighteenth century Clarke gave, and subsequently published, two sets of Boyle lectures. These lectures were named for Robert Boyle, who had left money in his will to support a set of eight sermons annually “for proving the Christian religion against notorious Infidels, viz. Atheists, Theists, Pagans, Jews, and Mahometans” (Boyle 1772, 1:clxvii). Clarke’s first set of Boyle lectures was published in 1705 as A Demonstration of the Being and Attributes of God (Clarke 1998). His second set was published in 1706 as A Discourse Concerning the Unchangeable Obligations of Natural Religion, and the Truth and Certainty of the Christian Revelation (Clarke 1738, 2:579–733). In the Discourse we find a version of the view that morality depends on relations.25

Introducing his Discourse, Clarke announces fifteen propositions he will prove. Ultimately, Clarke wants to persuade his readers, and the deists he opposes, of the truth and certainty of Christianity. He begins, however, in the first proposition by laying down certain general views about morality. Here is that first proposition.26

THAT the same necessary and eternal different Relations, that different Things bear one to another; and the same consequent Fitness or Unfitness of the Application of different Things or different Relations one to another, with regard to which the Will of God always and necessarily does determine itself to choose to act only what is agreeable to Justice, Equity, Goodness and Truth, in order to the Welfare of the whole Universe; ought likewise constantly to determine the Wills of all subordinate rational Beings, to govern all their Actions by the same Rules, for the Good of the Publick in their respective Stations. That is; these eternal and necessary differences of Things, make it fit and reasonable for Creatures so to act; they cause it to be their Duty, or lay an Obligation upon them, so to do; even separate from the consideration of these Rules being the positive Will or Command of God; and also antecedent to any respect or regard, expectation or apprehension, of any particular, private and personal Advantage or Disadvantage, Reward or Punishment, either present or future, annexed either by natural consequence, or by positive appointments, to the practising or neglecting those Rules (Clarke 1738, 2.596; cf. 2:608).

Several pages early in the Discourse are devoted to the proof and discussion of this proposition, and its defense against alternative views, especially that of Hobbes.27 Beginning his argument for the proposition, Clarke makes clear his commitment to the view that morality depends on relations.

Clarke states, seemingly as a general principle, that objects stand in various relations to one another, and, because of those relations, there is a “fitness or unfitness of the application of different things or different relations one to another” (Clarke 1738, 2:608). He then offers various instances of fitnesses arising from relations. For instance, “from the different relations of different Persons one to another, there necessarily arises a fitness or unfitness of certain manners of Behaviour of some persons towards others” (Clarke 1738, 2:608). In a different example, “God is infinitely superior to Men”, and therefore it is “certainly Fit, that Men should honour and worship, obey and imitate God” (Clarke 1738, 2:608). Clarke goes on to make various other claims about what is fitting, often with less explicit attention to the underlying relations. Throughout the discussion, Clarke says that these moral claims are as obvious as equivalent ones in mathematics.

In Clarke’s view of these matters, there are three connected items. First, there is the underlying relation between things. Second, there is a fitness of behavior, consequent on that relation. And third, there is an obligation on rational beings to behave in that fit manner.

The basic question we need to ask about the underlying relation is: What is it? In Malebranche’s view, the basic relation is more perfect than. For Locke, moral good and evil are founded on the relation of conformity, specifically conformity to the divine law. One might expect something similar in Clarke: a single relation, or at most a single sort of relation, underlying morality. Instead, we find a number of different relations, each of which Clarke thinks can give rise to an appropriate fitness, and thus to obligation.

In the Discourse, Clarke announces confidently that he might, from the basis he has described, “deduce in particular, all the several Duties of Morality or Natural Religion” (Clarke 1738, 2:618). But because this would take too long, he says that he “shall only mention the three great and principal Branches, from which all the other and smaller instances of duty do naturally flow, or may without difficulty be derived” (Clarke 1738, 2:618). These three are a duty (or set of duties) to God, duties to other people, and duties to ourselves. If we look at Clarke’s arguments about these three sets of duties, we find him appealing to several different underlying relations.

In the case of the duties to God (for instance, to worship him) we find relations similar to the relations of perfection in Malebranche’s account. If one were to summarize Clarke’s discussion very quickly, one could say that the underlying idea is that God is more perfect than us, so it is fit and proper that we worship him. But even here, Clarke gives more detail and invokes more relations. Different attributes of God give rise, Clarke argues, to different obligations. Thus, for example, “consideration of his Eternity and Infinity, his Knowledge and his Wisdom, necessarily commands our highest Admiration”, but “His Supreme Authority, as being the Creator, Preserver, and absolute Governour of all Things, obliges us to pay him all possible Honour and Veneration, Adoration and Worship” (Clarke 1738, 2:618). The comparison between God’s eternity and our finitude grounds our obligation to admire God, while the relation between creator and created grounds the obligation to worship. That is, we are to admire God for his knowledge but worship him because of his power.

When we look at the second set of duties, to other people, we see different relations at work. Clarke deduces two fundamental duties to other people: “In respect of our Fellow-Creatures, the Rule of Righteousness is; that in particular we so deal with every Man, as in like Circumstances we could reasonably expect he should deal with Us; and that in general we endeavour, by an universal Benevolence, to promote the welfare and happiness of all Men. The former Branch of this Rule, is Equity; the latter, is Love” (Clarke 1738, 2:619).

In the equity case, Clarke points to relations as follows: “Whatever relation or proportion one Man in any Case bears to another; the same That Other, when put in like Circumstances, bears to Him. Whatever I judge reasonable or unreasonable for another to do for Me; That, by the same Judgment, I declare reasonable or unreasonable, that I in the like Case should do for Him” (Clarke 1738, 2:619). According to that reasoning, equity does not arise from some general relation that I always bear to others; rather, it is the result of different people, when put in the same position in the same situation, standing in the same relations as others would when in those positions. This approach allows for a wide variety of relations to be invoked. Consider as examples the relations of parent and child, teacher and student, doctor and patient.28

One might wonder whether the obligations could arise from a different relation: that of conformity to the rule of righteousness.29 And Clarke does say that there is “a formal Obligation upon every man, actually and constantly to conform himself to that Rule” (2:618). But what is the basis of that rule? It cannot simply be a voluntaristic matter of divine command, given Clarke’s earlier arguments. Fundamentally, obligations arise from fitnesses, which arise from relations. In the case of equity, those are the relations between people described in the previous paragraph. Someone might, within Clarke’s system, guide their action just by attending to the rule of righteousness, which they take to be commanded by God. But although that person might act correctly, they would not be paying attention to the ultimate basis of their obligations.

The deduction of the duty of love and benevolence is harder to connect to relations and subsequent fitnesses, as they do not figure in Clarke’s arguments in the same way. Clarke does gesture towards a connection to his earlier discussions: “The Obligation to which duty also, may easily be deduced from what has already been laid down” (Clarke 1738, 2:621). He goes on to argue that “that which is Good is fit and reasonable … and that which is the greatest Good, is always the most fit and reasonable to be chosen …so every rational Creature ought … to do all the Good it can it its Fellow-creatures” (Clarke 1738, 2:621). This suggests that duties of love and benevolence are grounded on all the same fitnesses, and thus on the same relations, that ground other obligations. But Clarke here introduces a notion of being “most fit” which both needs more explanation and does not obviously connect to benevolence—it might seem to push us towards doing the action that is most carefully and precisely proportioned to the situation, rather than going beyond this into benevolence.

A further argument begins from “a certain natural Affection” (Clarke 1738, 2:622) within us. Later, Clarke appeals to the ways that love and benevolence are necessary for society, which is necessary for human beings. Neither of those considerations connects easily to fitnesses and relations as they had been discussed previously. Perhaps, as with equity, one might suggest that duties of love and benevolence are grounded in conformity to the rule of righteousness. But again, the rule itself is not fundamental, and though one might guide one’s actions by conforming to a divinely commanded duty of benevolence, there ought to be some further explanation of how the duty arises. Though Clarke clearly wants to ground the duty of love and benevolence on relations and finesses, it remains less clear than in other cases how the grounding is supposed to work.

However, the third basic duty, the duty to oneself, is clearly justified with reference to a relation: “That every Man ought to preserve his own Being as long as he is able, is evident; because what he is not himself the Author and Giver of, he can never of himself have just Power or Authority to take away” (Clarke 1738, 2:623). This is a relation to God: not the relation of being less perfect than God, but the relation of being created by God.

Clarke appeals repeatedly to the relations between humans and God as a source of moral obligation, but other moral obligations arise from the relations between human beings. Thus, although there is some similarity between aspects of Clarke’s view of the basic relations and Malebranche’s, they have rather different approaches.

Clarke’s story about the origin of those obligations involves the presence of a certain fitness, arising from relations. There is a rather obvious question here; namely, what is fitness? In some basic sense it is appropriateness (or, in other words, propriety). For instance, Clarke thinks that because God is eternal, and I am finite and limited, it is fit or appropriate or proper that I admire God.

That may be so, but how do we get from relation to fitness? One might think there needs to be another premise involved. That is, we seem to need more than the bare fact that God created humans to get to the conclusion that it is fit and appropriate for humans to worship God—we seem to need a further commitment to the fitness of worshiping creators. Indeed, if this line of thought is right, we will need multiple such commitments, corresponding to the different relations invoked by Clarke.

That might seem a plausible approach, but does Clarke accept it? One might well get the impression from his writing that the fitnesses are supposed to arise directly from the relations, without anything extra being involved. Certainly, we get the sense from Clarke that this is how things are supposed to appear to us: that we, so to speak, just see the fitness of certain actions when we see the relations between things. Thus, Clarke comments at the end of his discussion of Plato’s Meno that “the Mind of Man naturally and unavoidably gives its Assent, as to natural and geometrical Truth, so also to the moral differences of things, and to the fitness and reasonableness of the Obligation of the everlasting Law of Righteousness, whenever fairly and plainly proposed” (Clarke 1738, 2:615).30

However we take the exact process to work, Clarke clearly thinks that the relations of humans and God give rise to the fitness of various actions. One might suspect that an action being fitting just is, or immediately gives rise to, a duty or obligation to do it. But Clarke argues separately that we human beings ought to perform the fitting actions.

Clarke claims that the wills “of all Intelligent Beings” are directed by those beings’ understandings of relations and consequent fitnesses, unless those wills have been “corrupted by particular Interest or Affection, or swayed by some unreasonable and prevailing Passion” (Clarke 1738, 2:612). God, free of such corruptions, is always guided by relations and fitnesses. Developing that thought, Clarke argues that we “Subordinate Rational Beings” (Clarke 1738, 2:612) ought, despite our weaknesses, to act according to “the eternal Rules of Justice, Equity, Righteousness and Truth” (Clarke 1738, 2:613). Those rules are themselves a result of relations and fitnesses. If we were like God, we would always follow the moral rules. Being weak and corrupted creatures, we will not always do so, because there are other internal influences on our actions. Nevertheless, we ought always to act according to moral rules.31

Given the possibility of divine reward and punishment, there are prudential motives to follow moral rules. But Clarke argues that that the obligation to do so is “antecedent to all Consideration” (Clarke 1738, 2:627) of reward and punishment. That consideration may provide an extra motive, but it is not the fundamental reason why one ought to follow the law.32

Throughout all of this we see, as in Malebranche and Locke, a comparison to mathematics. For instance, one of Clarke’s thoughts about the obligation is:

that in like manner as no one, who is instructed in Mathematicks, can forbear giving his Assent to every Geometrical Demonstration, of which he understands the Terms, either by his own Study, or having had them explained to him others; so no man, who either has patience and opportunities to examine and consider things himself, or has the means of being taught and instructed in any tolerable manner by Others, concerning the necessary relations and dependencies of things; can avoid giving his Assent to the fitness and reasonableness of his governing all his Actions by the Law or Rule before mentioned, even though his Practice, through the prevalence of Brutish Lusts, be most absurdly contradictory to that Assent (Clarke 1738, 2:614).

As reason compels us to acknowledge various truths in mathematics, so, according to Clarke, it compels us to acknowledge this obligation.

In summary, then, Clarke, as well as Malebranche and Locke, gives us a metaphysical view on which morality is founded on relations. It is founded on several different relations: relations between people, and relations between people and God. Clarke thinks those relations give rise to the fitness of certain actions, and thus to obligations to perform those actions. And all these things can be known, if clearly presented, in something like the way that mathematics can be known.

5. Conclusion

I have looked at three philosophers writing before Hume: Malebranche, Locke, and Clarke. One can fairly say that each of the three thought morality was founded on relations. Indeed, each held a metaphysical view about the relations that ground morality. Malebranche thought they were relations of perfection, such as more perfect than. Locke thought the key relation was conformity, in particular, conformity to the divine law. Clarke thought multiple relations—both relations between people and relations between us and God—were among the foundations.

Epistemological views also play an important role. All three repeatedly compared moral knowledge to mathematical knowledge. They were not the only philosophers to do so, but the persistent use of the comparison is notable. Its presence might explain why Hume connected the view that morality was founded on relations to the view that it was known by, or otherwise founded on, reason rather than sentiment. Malebranche and Locke, if not Clarke, also tried to provide theoretical underpinnings for the claim that the two fields are epistemologically similar. Beyond that, both Malebranche and Locke held views of knowledge which implied that knowledge of moral truths must in some sense be knowledge of relations. In Locke this involves, or perhaps just is, the view that knowledge, including moral knowledge, is propositional, being awareness of relations between ideas. In Malebranche, we find an underlying view that all truths are relations, which is perhaps again the view that moral knowledge is propositional. But we also find the view that moral truths are, like mathematical ones, relations between ideas.33

This is not an exhaustive history of early modern views according to which morality is founded on relations, but it does show that there is an interesting history here, one suggested, but not clearly revealed, by Hume’s references. At least, I hope to have explained what these three pre-Humean philosophers themselves meant when they claimed that morality was founded on relations.

Despite the connections we have seen, one might still wonder how much these three philosophers had in common. Their respective metaphysical views—Malebranche’s relations of perfection view, Locke’s conformity to divine law view, and Clarke’s view about relations and fitnesses—seem entirely different from one another. In searching for an underlying metaphysical position they hold in common, one finds perhaps the view that an agent’s moral status is not solely a matter of their own intrinsic nature but also involves their relation to something else. But this is so general that it may be harder to find people who disagree with it than those who do. And the apparently disjointed nature of Hume’s criticism of the view that morality is founded on relations reinforces the sense that there may be no unified view here.

Nevertheless, we might hope to find some answer to what the views have in common by looking at Hume’s criticisms of them. With that in mind, I turn now to those criticisms as we find them in the Treatise and the moral Enquiry. My main aim is not to show something about Hume in light of what we have already seen, but rather to see if Hume’s criticisms shed any light on what the various views involving relations have to do with one another.

Treatise 3.1.1, “Moral distinctions not deriv’d from reason,” includes two main sets of arguments against Hume’s opponents. In the first set (Treatise 3.1.1.5–16), Hume argues, based on views about what can influence passion, volition, and action, that it is “impossible, that the distinction betwixt moral good and evil, can be made by reason” (Treatise 3.1.1.16). In the second set (Treatise 3.1.1.17–27), Hume argues against the Clarkean fitness view in particular.34 That discussion opens with an argument in a Humean framework (Treatise 3.1.1.18–19). Hume contends that the “character of virtuous and vicious” must consist of either a relation or a matter of fact. He argues that it cannot be a matter of fact, and also cannot be any of the four “relations susceptible of certainty and demonstration” previously identified. Hume continues by responding to the notion that some other relation might be involved (Treatise 3.1.1.20–23). Such a relation must, he argues, meet two conditions. First, it must apply to, and only to, the relations between “internal actions” and “external objects” (Treatise 3.1.1.21). This itself would rule out the relations to which Clarke appeals. Second, it must have an appropriate influence on the will. Here, Hume attacks the Clarkean view that relations and fitnesses influence God’s will as well as (indeed more than) our own. Hume argues that you cannot prove “a priori, that those relations, if they really existed and were perceiv’d, wou’d be universally forcible and obligatory” (Treatise 3.1.1.23).35 Towards the end of Treatise 3.1.1, we also see Hume arguing that the very same relations that have moral significance when they hold between humans have no moral significance when they hold between trees or even animals (Treatise 3.1.1.24–5).36

Clarke is the only opponent whose view receives sustained, direct attention in Treatise 3.1.1. There is much briefer criticism of William Wollaston.37 And we might wonder if 3.1.1.18, which attacks the view “that morality is susceptible of demonstration”, is supposed to be a criticism of Locke. But that discussion appears intended to target Clarke as well, given that 3.1.1.20 frames the Clarkean as introducing new demonstrable relations. In general, holders of non-Clarkean relational views, such as Malebranche and Locke, are presumably taken to be refuted by the general Humean argument, without detailed engagement.

Hume’s focus on Clarke does mean, however, that Treatise 3.1.1 cannot tell us much about what Malebranche, Locke, Clarke might be supposed to have in common. But interestingly, in Treatise 3.1.1, Hume does seem to be committed to thinking that Clarke’s views involving fitnesses go along with a commitment to moral demonstrations. While it is not obvious that those things go together—it looks as if one might believe in the metaethics of fitnesses without believing in the moral epistemology of demonstrations and vice versa— Hume seems to think that his opponents, including Clarke, connect them.38

In Appendix 1 of the Enquiry concerning the Principles of Morals, Hume presents five numbered arguments, the first four of which are directed against the view that morality depends on relations. The first is aimed directly at the view that morality involves relations of ideas rather than matters of fact. The second is based on differences between considering relations in geometry and in morality. The third involves a comparison to natural beauty (which, Hume argues, depends on geometrical relations, but is not identical to them). And the fourth provides an alleged counterexample, in which the relations between inanimate objects are the same as those between moral agents.

Those arguments give few detailed clues as to which opposing views Hume has in mind. Hume does at one point consider the view that “morality consists in the relation of actions to the rule of right” (EPM App.1.9), which might initially sound like Locke’s view that moral goodness consists in conformity to divine law. Even there, however, Hume does not consider a Lockean version of the view, but one in which the rule itself “is determined by considering the moral relations of objects”. That is, Hume is considering something more like Clarke’s talk of moral rules than anything in Locke. In his criticisms, Hume seems to be thinking mostly about a combination of Clarke’s position and the view that morality is founded on Humean relations of ideas.

In these criticisms of the view that morality is founded on relations, Hume ignores several versions of that view: versions which he knew about and pointed out in the footnote with which this paper begins. If he has one opponent in mind, that is Clarke. Despite having named Malebranche as the originator of the view that morality was founded on relations, and despite his knowledge of Malebranche’s work, Hume here ignores Malebranche’s relations of perfection view and Malebranchean epistemology. Hume does consider the seemingly Lockean view that that morality is a possible subject of demonstration, but he does not consider Locke’s view that invokes conformity to divine law. In considering the little tradition he had earlier constructed, according to which morality is founded on relations, Hume ignores the aspects of that tradition that invoke God in giving explanations. The same is largely true of the earlier discussion in Treatise 3.1.1. Perhaps Hume thought that ethical views making fundamental reference to God were best ignored, for they were not plausible candidates for further development, at least not within Hume’s project of developing a secular account of morality.

Taking this omission of God-involving views to be intentional, I agree with Russell (2008, 244) in rejecting the view that “issues of religion do not shape and structure Hume’s basic arguments and aims as concerns his moral theory.”39 Now, saying that Hume deliberately omitted views that made fundamental reference to God might seem odd, given his discussions of Clarke. Clarke, after all, was a religious moralist whose views Hume thought worth discussing.40 Indeed, Treatise 3.1.1.22 considers Clarke’s views on God’s actions. But one might consider a God-free version of the Clarkean view that morality arises from relations between agents in a way that one could not consider a God-free version of, say, Locke’s divine command view. And Hume would reject anything presented as a God-free version of Clarke’s view, as well as the actual, more religiously embedded version. Indeed, Hume generally focuses on the part of Clarke’s view that concerns relations giving rise to fitnesses and obligations, which can be considered without reference to God.41 This might be a candidate secular moral theory, even though Clarke did not present it as such.

In the actual tradition of taking morality to be founded on relations, God-involving views had a prominent place. I say “the actual tradition,” though it is very much open to consideration whether there was anything worth calling a tradition. Still, the three philosophers whom I have discussed held one more curious thing in common: all three very much wanted to say that morality was founded on relations. Each of them chose, even when that choice might be surprising to us, to emphasize this aspect of their positions. Malebranche insisted that the foundation of his view lay in relations of perfection. He did this despite the fact that it seems just as easy to find the foundation in a view about levels of perfection, with the relations of perfection between different objects being derivative of their levels of perfection. In Malebranche’s presentation, relations are paramount. In Locke’s Essay, meanwhile, the account of moral goodness is given in an account of moral relations, which sits itself within a more general discussion of relations. There are other places Locke could have given this account, but he too wanted to emphasize that the basic foundations of morality were a matter of relations. In Clarke, the emphasis on relations is, if anything, even stronger. Indeed, it is Clarke who gave what might seem to us to be the most obvious relational account of morality, that is, as a matter of the relations between agents. But it was not just Clarke who wanted to emphasize the presence of relations: all three philosophers did this.

That fondness for the language of relations is genuine, as are the various underlying metaphysical and epistemological commitments. Seeing the similarities in the language used can help us uncover genuine points of connection. Now, talk of relations is not the one key to understanding pre-Humean rationalist or Platonist modern philosophy—there is no such one key. Faced with the work of Malebranche, Locke, Clarke, and others, we can trace various lines thorough their debates. One might, for instance, emphasize the epistemological use of reason, or the possibility of demonstration, or the fondness of some philosophers for direct reference to Plato and other Platonists. Any one of those connects a slightly different group of philosophers in a slightly different way. Hume’s picking out of those who founded morality on relations is yet another intriguing way of finding a line through that debate.42

Notes

  1. Montesquieu began his book by saying that “Laws, taken in the broadest meaning, are the necessary relations deriving from the nature of things” (Montesquieu 1989, 3). [^]
  2. Such opinions were not just epistemological—consider the view that moral truths are grounded in, not merely known by, our emotional reactions to the world. Consider too how philosophers talked about reason as more than just a human mental faculty. Malebranche identified reason with “the Word or the Wisdom of God Himself” (Malebranche 1993, 45), Locke at one point identified it with the “Law of Nature” (Second Treatise 2.6; Locke 1988, 271), and Clarke talked about “the eternal Reason of Things; That Reason, which God himself … constantly obliges himself to govern the World by” (Clarke 1738, 2:614). All three passages take reason, in some primary sense, to be God’s reason. [^]
  3. For example, “I accept that some relations are sources of agent-relative moral reasons. For example, that a person is a member of my immediate family may give me a moral reason to treat that person more generously than I am required to treat people who are not members of my family” (McMahan 2005, 359). McMahan goes on to discuss what relations are special in this way. [^]
  4. In recent discussions, one might think of Stephen Darwall’s arguments that “many central moral concepts … have an irreducibly second-personal structure” (Darwall 2013). [^]
  5. I do not discuss Cudworth or Montesquieu here. Although Cudworth thought morality was known by reason, and that reason could know relations, it is much less clear that he thought morality was founded on relations. Montesquieu’s book was first published in 1748, eight years after volume 3 of the Treatise, and so is not really part of the pre-Humean discussion on which I focus. [^]
  6. The joining of metaphysical and epistemological aspects is visible in Kail’s summary of moral rationalism as “the claim that moral facts consist in relations, and the epistemology of morality is the epistemology of relations, the discovering of which depends on reason’s comparisons of the ideas of the relevant objects” (Kail 2017, 318). [^]
  7. Matters of fact, in contrast, are not “discoverable by the mere operation of thought”. Moreover, they are not necessary truths: “The contrary of every matter of fact is still possible; because it can never imply a contradiction” (EHU 4.2). [^]
  8. The claim that relations of ideas are intuitively or demonstratively certain and include mathematical knowledge looks like Locke’s account of things which are known intuitively or demonstratively. The claim that there is nothing outside the mind to be known in these cases looks like Locke’s discussions of mathematics and morality, in which he thinks we can give demonstrations, and in which he says we are dealing with mixed modes. In this realm, Locke thinks, the archetypes are purely mental and internal: there is no sense in which we should be matching our ideas to some extra-mental objects. [^]
  9. For example, EPM App.1.6 is about the Humean relations of ideas view, but Treatise 3.1.1.4 is about Clarke’s account. [^]
  10. This is documented by McCracken (1983, 254–90). McIntyre and Walsh (2022) and Pyle (2019) provide recent discussions of detailed connections. [^]
  11. On Malebranche on relations of perfection, see Riley (2000, 240–5). [^]
  12. Underlying all this is Malebranche’s view that we perceive ideas in the mind of God, and his own understanding of these positions depends on that. [^]
  13. On the issue of all human beings having the same degree of perfection, and the moral consequences of this, see McIntyre and Walsh (2022, 9). [^]
  14. For Hume, the faculty of reason does less of the psychological work than others thought it did—for Hume, it is not reason that takes us from experience to expectation and predication (EHU 4–5)—but Hume does not deny that reason exists, or that it has a role to play in the workings of the mind. [^]
  15. Pyle (2019) quotes the same passage from Malebranche, and provides a useful discussion. Consider also McCracken (1983, 274): “Malebranche and Hume both thought that knowledge depends on a perception of relations. Many others, including Locke, had thought so too, but the similarities here between our two thinkers are striking”. [^]
  16. “Mathematics, metaphysics, and even a large part of physics and morals contain necessary truths” (Malebranche 1997, 15). [^]
  17. Aspects of Essay 2.28 suggest a different view: that the divine law is the standard of moral good and the law of opinion is the standard of virtue. See for instance the way the discussion is outlined in 2.28.7. But not only does Locke say that the divine law is “the only true touchstone of moral Rectitude” (Essay 2.28.8), he also says that the law of opinion is the “common” (2.28.11), not the correct, standard of virtue. Locke emphasizes that second point in his reply to James Lowde’s criticisms (Lowde 1694, preface). Locke says that, where 2.28 seemed to Lowde to say that virtue and vice are determined by the law of opinion, he (Locke) was just talking about what people call virtue and vice, not what virtue and vice really are (Essay 2.28.11n.). [^]
  18. Thus Kail, describing Locke’s view under the heading of “moral rationalism”: “moral knowledge yields knowledge by yielding knowledge of conceptual relations, and moral facts are conceptual relations” (Kail 2017, 316). [^]
  19. On evidence for that reading, see Mattern (1978, 682–3). As Mattern (1978) and Weinberg (2021) discuss, there are puzzles involved in understanding how Locke could have consistently held that view, but he does appear to have held it. [^]
  20. Ultimately Locke’s suggestion is not merely that there might be demonstrations in morality, but also that one might found a whole science of morality on two ideas: the idea of God, and our idea of ourselves as understanding, rational beings (Essay 4.3.18). [^]
  21. Wilson (2007, 398) argues that Locke “seemed to lose confidence in his view that morality is demonstrable”, citing passages from letters Locke wrote to Molyneux in 1692 and 1696 (Locke 1976–89, 4:524, 5:595). These seem however not to show Locke thinking that morality cannot be demonstrated. They tend instead to confirm that Locke thought constructing a demonstrative science of morality was a difficult task that had not been done. Kemp (1964, 20) describes Locke as offering excuses for not writing the systematic work of demonstrative ethics Molyneux thought he should write. Note also Locke’s comment in the Reasonableness of Christianity that “whatever else was the cause, it is plain, in fact, that human reason unassisted failed men in its great and proper business of morality. It never from unquestionable principles, by clear deductions, made out an entire body of the ‘law of nature’” (Locke 1824, 6:140). [^]
  22. See Waldron (2002, 94–106) and LoLordo (2012, 14–17) on how much reason can accomplish, and how that compares to the possibilities of learning about morality in other (particularly religious) ways. [^]
  23. One might argue Locke does not really fit, because Hume has a sort of rationalism in mind, which only the epistemological part of Locke’s view fits, not the voluntaristic part. That is tempting, but if we think the view Hume had in mind was narrower than merely the view that morality is founded on relations, it is quite difficult to say in a principled way what it might have been. At least, it is difficult to do so in a way that does not apply to Locke but still applies to Malebranche and Clarke. For instance, one way to do it would be to narrow one’s focus to the view that morality is a matter of Humean relations of ideas, but that includes neither Malebranche’s view that morality depends on relations of perfection between ideas in the mind of God nor Clarke’s view. [^]
  24. For obvious examples beyond the engagement in moral philosophy, see the discussion of Clarke’s argument that everything must have a cause at Treatise 1.3.3 and the reference to Clarke in part 9 of the Dialogues concerning Natural Religion. On the relationship between Hume’s work (in particular the Treatise) and Clarke’s, see Russell (2008). [^]
  25. A more comprehensive history would also consider the views of John Balguy. In the relevant section of his 1728 Foundation of Moral Goodness, Balguy refers approvingly to Clarke’s Boyle lectures and talks—as Clarke does—of fitnesses, relations, and reason (Raphael 1991, 1:397–9). [^]
  26. General accounts of Clarke’s approach to these topics can be found in Botros (2006, 62–72), Irwin (2008, 372–98), Kail (2017), Kemp (1964, 27–38), Mackie (1980, 12–20), and Thomas (1997), who also refers to earlier discussions of Clarke by Sidgwick, Martineau, and Pritchard. [^]
  27. This is the part of Clarke’s work that is excerpted in Raphael (1991, 1:191–225). [^]
  28. There are, Clarke acknowledges, some complications in thinking about what equity says about the “Duties of Superiours and Inferiours in various Relations” (2:620). Consider the duties of parents and children. The duty of the parent is not what the child, with their current commitments, desires, and relationships, would want, if somehow in the parent’s position. For to consider that is not fully to consider the child in the parent’s position. [^]
  29. I thank an anonymous referee for this suggestion. [^]
  30. Mackie (1980, 19) seems to read Clarke in this way: “There is, then, some truth in Clarke’s claim that ‘the mind of man cannot avoid giving its assent to the eternal law of righteousness.’ We seem to see requirements to act or not to act in certain ways as arising directly out of the hard facts of the situations in question, as directly supervenient upon the natural features of those situations and the proposed actions” (Mackie 1980, 19). But as Mackie goes on to say, “this falls far short of a demonstration of these requirements as necessary consequences of those natural features”. [^]
  31. There’s another question one might ask here, about why fitness conclusively settles what we ought to do, rather than being one of the relevant considerations alongside, say, prudence. See Debes (2014: 510–1). [^]
  32. Clarke also argues that the obligation of the law of nature is in some sense prior to its being God’s command (Clarke 1738, 2:626). This is at least the Euthyphro-type point that things are commanded to us because they are good, not vice versa. Though Plato is not cited there, he is present in Clarke’s discussion. Clarke invokes the discussion of recollection in the Meno, adding that one could get to moral truths as well as geometrical ones by the method of questioning described there, but not agreeing that there is recollection involved, or even innateness (Clarke 1738, 2:615). We also find references to the Laws (2:616–7) and Phaedo (2:623). Plato is not the only ancient author to whom Clarke repeatedly refers. In this part of the text, Cicero is cited repeatedly (2.602–3, 2.610, 2.616–9, 2.620, 2.622–6, 2.628–9). Among more recent authors, Clarke’s most frequent reference—aside from references to Hobbes for the purpose of arguing against him—is to Cumberland, De Legibus Naturae. [^]
  33. These epistemological views are related to the view that morality is founded on Humean relations of ideas—with the significant qualification that Malebranche was talking about ideas in the mind of God, not of human beings. [^]
  34. Perhaps Hume was thinking about Balguy (see note 24 above) as well as Clarke. [^]
  35. Hume’s general point about the transition to the practical (in, e.g., Treatise 3.1.1.22, 3.1.1.27) does strike at something Clarke assumes and one might reject. [^]
  36. Clarke might try to reply to this point by being more precise about the relations involved. [^]
  37. See Treatise 3.1.1.15. We might perhaps think of Wollaston as having a sort of relational view, the relevant relation being conformity to the truth. He does use the language of conformity—“if the formal ratio of moral good and evil be made to consist in a conformity of men’s acts to the truth of the case or the contrary, as I have here explained it”—which suggests one might explore such an interpretation (Raphael 1991, §293). [^]
  38. See also Hume’s Letter to a Gentleman: “He hath indeed denied the eternal Difference of Right and Wrong in the Sense in which Clark and Woolaston maintained them, viz. That the Propositions of Morality were of the same Nature with the Truths of Mathematicks and the abstract Sciences, the Objects merely of Reason, not the Feelings of our internal Tastes and Sentiments” (Hume 2007, 429). [^]
  39. This is not to endorse the whole of Russell’s “irreligious interpretation”. [^]
  40. See Russell (2008, 243–8), or just think about the overall purposes of Clarke’s Discourse, beyond the discussion of the first proposition. [^]
  41. Could there be a God-free version of Malebranche’s view about relations of perfection? One could, for instance, construct such a thing in terms of Humean relations of ideas, but it would not be much like Malebranche’s actual view. [^]
  42. I’d like to thank audiences at the University at Buffalo and the University of Florida for helpful discussions of this material. [^]

Competing Interests

The author has no competing interests to declare.

References

Botros, Sophie. 2006. Hume, Reason and Morality: A Legacy of Contradiction. Abingdon: Routledge.

Boyle, Robert. 1772. The Works of the Honourable Robert Boyle in six volumes. London.

Clarke, Samuel. 1738. The Works of Samuel Clarke. London.

Clarke, Samuel. 1998. A Demonstration of the Being and Attributes of God and Other Writings. Edited by Ezio Vailati. Cambridge: Cambridge University Press.

Darwall, Stephen. 2013. “Introduction”. In Morality, Authority, and Law: Essays in Second-Personal Ethics I (Oxford: Oxford University Press), online edition, pages un-numbered.

Debes, Remy. 2014. “Moral Rationalism and Moral Realism”. In Aaron Garrett (ed.), The Routledge Companion to Eighteenth Century Philosophy (London: Routledge) 500–34.

Hume, David. 1998. An Enquiry concerning the Principles of Morals. Edited by Tom L. Beauchamp. Oxford: Clarendon. [EPM].

Hume, David. 2000. An Enquiry Concerning Human Understanding. Edited by Tom L. Beauchamp. Oxford: Clarendon. [EHU].

Hume, David. 2007. A Treatise of Human Nature. Edited by David Fate Norton and Mary J. Norton. Oxford: Clarendon. [Treatise]

Irwin, Terence. 2008. The Development of Ethics: A Historical and Critical Study. Volume II: From Suarez to Rousseau. Oxford: Oxford University Press.

Kail, P.J.E. 2017. “Moral Judgment”. In James A. Harris (ed.), The Oxford Handbook of British Philosophy in the Eighteenth Century (Oxford: Oxford University Press) 315–32.

Kemp, J. 1964. Reason, Action and Morality. London: Routledge & Kegan Paul.

Locke, John. 1824. The Works of John Locke. London.

Locke, John. 1975. An Essay concerning Human Understanding. Edited by P.H. Nidditch. Oxford: Clarendon. [Essay]

Locke, John. 1976–89. The Correspondence of John Locke. Edited by E.S. de Beer. Oxford: Clarendon.

Locke, John. 1988. Two Treatises of Government. Edited by Peter Laslett. Cambridge: Cambridge University Press.

LoLordo, Antonia. 2012. Locke’s Moral Man. Oxford: Oxford University Press.

Lowde, James. 1994. A Discourse Concerning the Nature of Man. London.

Mackie, J.L. 1980. Hume’s Moral Theory. London: Routledge.

Malebranche, Nicolas. 1993. Treatise on Ethics (1684). Translated by Craig Walton. Dordrecht: Kluwer.

Malebranche, Nicolas. 1997. The Search after Truth. Translated by Thomas M. Lennon and Paul J. Olscamp. Cambridge: Cambridge University Press.

Mattern, Ruth Marie. 1978. “Locke: ‘Our Knowledge, Which All Consists in Propositions”. Canadian Journal of Philosophy 8: 677–95.

McCracken, Charles. 1983. Malebranche and British Philosophy. Oxford: Clarendon.

McMahan, Jeff. 2005. “Our Fellow Creatures”. The Journal of Ethics 9: 353–80.

McIntyre, Alison and Julie Walsh. 2022. “Self-Love or Diffidence? Malebranche and Hume on the Love of Fame”. Journal of Modern Philosophy 4(2): 1–24.

Montesquieu, Charles de Secondat. 2009. The Spirit of the Laws. Translated and edited by Anne M. Cohler, Basia Carolyn Miller, and Harold Samuel Stone. Cambridge: Cambridge University Press.

Popkin, Richard H. 1964. “So, Hume Did Read Berkeley”. Journal of Philosophy 61: 773–8.

Pyle, Andrew. 2019. “Malebranche”. In Stephen Gaukroger (ed.), Knowledge in Modern Philosophy (London: Bloomsbury) 79–96.

Raphael, D.D. (ed.) 1991. British Moralists 1650–1800. Indianapolis: Hackett.

Riley, Patrick. 2000. “Malebranche’s Moral Philosophy: Divine and Human Justice”. In Steven Nadler (ed.), The Cambridge Companion to Malebranche (Cambridge: Cambridge University Press) 220–61.

Russell, Paul. 2008. The Riddle of Hume’s Treatise: Skepticism, Naturalism, and Irreligion. New York: Oxford University Press.

Thomas, D.O. 1997. “Reason and Revelation in Samuel Clarke’s Epistemology of Morals”. Enlightenment and Dissent 16: 114–35. Electronic version, available at https://www.qmul.ac.uk/sed/religionandliterature/media/centre-for-religion-and-literature-in-english/E&D-16-(1997).pdf.

Weinberg, Shelley. 2021. “Locke’s Knowledge of Ideas: Propositional or by Acquaintance?” Journal of Modern Philosophy 3(4): 1–18.

Wilson, Catherine. 2007. “The Moral Epistemology of Locke’s Essay”. In Lex Newman (ed.), The Cambridge Companion to Locke’s Essay Concerning Human Understanding (Cambridge: Cambridge University Press) 381–405.