Whether or not the passage from Lessing is to be taken literally, the most straightforward way to account for the power of beauty, or indeed anything, is to regard it as having causal efficacy. After all, non-causal ways of making things happen have not been theorized to the same extent that causation has. It is therefore worth asking whether some of the most prominent theories of causation are at least compatible with a causal account of the power of beauty. These theories fall into two broad categories: regularity theories on the one hand, and counterfactual theories on the other.3 According to theories of the first kind, a cause is nomologically sufficient for its effect, or at least is an Insufficient but Non-redundant part of an Unnecessary but nomologically Sufficient (abbreviated to INUS) condition for its effect.4 (The meaning of “nomologically sufficient” here is that the occurrence of the effect is guaranteed by a lawlike regularity. More on this later.) According to theories of the second kind, effects depend counterfactually on their causes; in other words, and assuming that both are actual events, if the cause had not occurred, then the effect would not have occurred either.5 Consequently, the question to be asked is: what is to prevent us from regarding the beauty of an object as something like an INUS condition for being moved? Likewise, what is to prevent us from regarding the beauty of an object as a condition on which my being moved counterfactually depends?

In what follows, four replies to these questions are considered, each stating a different reason for objecting to a causal account of beauty’s power. The replies/objections can be summarized as follows:

The first three objections will be dealt with succinctly, in Sections 2, 3, and 4 respectively, with explanations of why the desired conclusion does not follow. However, dealing with the fourth objection will require a positive and novel account of how beauty exercises its causal power. It is in this account, to be offered in Section 5, that the paper’s point of gravity should be located.

Before we turn to the objections, two preliminary notes are in order.

Firstly, it will be assumed that beauty is a property of some of the things we experience as beautiful. Most, if not all, of the authors mentioned earlier share this realist assumption. Moreover, it is necessary to make this assumption to focus the issue on whether beauty has causal consequences, and if so, which ones. After all, if beauty is never a property of the things we experience as beautiful, then a fortiori it is never a property that has consequences, causal or otherwise, and the question of which causal consequences it has loses all pertinence.

Secondly, although the question to be settled here is whether beauty can have causal consequences, and if so, which ones, it is not assumed that properties are (the) causal relata. Indeed, it seems more plausible to me that facts or events are. So, the question really is whether the fact that something is beautiful, or the event consisting of something’s being beautiful, has causal consequences—if so, which ones? However, because the property of being beautiful figures in both the fact and the event, and all my major claims can be reformulated to conform to any choice of causal relata (whether properties, facts, or events), it seems fine to proceed with talk of beauty’s causal power both for ease of expression and for maintaining a clear focus.

One may object that there is no natural (for example, physical or psychological) law to underwrite nomological sufficiency when beauty is conceived as a non-natural property: that is, roughly speaking, a property that cannot be expressed in the language of the natural sciences, including neurophysiology and empirical psychology.6 Regularity theories, such as INUS theories, define causality in terms of nomological sufficiency and are therefore excluded, it seems, unless beauty is a natural property, contrary to the opinion of at least some philosophers.7

No doubt many will be tempted to grasp the second horn of the dilemma by affirming that beauty is a natural property. However, a better, or at least more oecumenical, response might be to recognize that the dilemma is a false one. Why assume that the only laws available to regularity theories of causation are natural laws, in the sense of laws discovered by the natural sciences? Although regularity theories have been developed with such laws in mind, it is not inconsistent with them to suppose that some of the causal facts are grounded in regularities involving non-natural properties. Even if the supposition led to inconsistency in some cases, this inconsistency could easily be removed by adopting a broader notion of lawlike regularity.

But what could be an example of a lawlike regularity featuring beauty? Here is one possible example: “If an object is beautiful, then people experiencing the object will experience it as beautiful.” Clearly, this generalization allows for too many exceptions to count as a law, so we need something like: “If an object is beautiful, then people who are receptive to beauty and who are experiencing the object will experience it as beautiful.” If beauty is a natural property, then it might be possible to specify the required receptivity (for example, at the neurophysiological level) without rendering the law vacuously true. After all, how a certain natural property gets detected is a non-trivial empirical question. Think, for example, of how one might specify what is required for working colour vision. However, if beauty is a non-natural property, then it is not clear how to specify the required receptivity. One might mention “taste” or “aesthetic sensitivity”, but these are just different names for the required receptivity. At the same time, one cannot stick with “receptive to beauty” without at least raising the suspicion that it is a mere placeholder for whatever makes people experience beauty in their environment. In other words, there is the risk that this phrasing renders the law vacuously true, so that it reads like something of the form: “If p, then, under the conditions that make q follow, q follows.”

In sum, we either conceive of beauty as a natural property or we had better look for an alternative to regularity theories of causation. However, at least at this stage of the investigation, neither option implies that we cannot think of beauty as a cause. For example, counterfactual theories of causation are still available as an alternative to regularity theories. (In Section 5, we will also encounter transference theories.)

One may object that neither nomological sufficiency nor counterfactual dependence makes sense when the object involved is abstract, yet some abstract objects are moving by virtue of their beauty. One could think here of the beauty of proofs, theories, and stories.8

Again, a plea for open-mindedness can be made. Perhaps abstract objects stand in temporal relations. For example, several philosophers believe that abstract objects such as musical and literary works can begin and cease to exist (Levinson 1980, Thomasson 1999, Lamarque 2010, Walters 2013). In addition, it is plausible to assume that, if something has a certain property atemporally, then it also has it temporally (provided that there is time). For example, if a certain (abstract) computational problem is atemporally NP-hard, then it is also presently NP-hard. Perhaps it is enough to have an event in which the problem participates, and why could an event of this type not feature in a lawlike regularity of the sort that regularity theories appeal to—say, “Whenever a computational problem is NP-hard, existing computers will not be able to solve it”?9

Counterfactual accounts of causation may seem to have a harder time accommodating abstract objects because, presumably, such objects are necessarily beautiful if beautiful. Because counterfactuals with necessarily false antecedents are trivially true (at least according to one account of them, i.e. Lewis 2001), it is trivially true that if the (beautiful) story had not been beautiful, then one would not have felt aesthetic pleasure. Equally, it is trivially true that if some other (beautiful) abstract object had not been beautiful, then one would not have felt aesthetic pleasure. It is even trivially true that if some (ugly) abstract object had not been ugly, then one would not have felt aesthetic pleasure. In sum, all abstract objects become (constituents of) causes of one’s pleasure—clearly an undesirable result.

However, it may be possible to make room for abstract objects within counterfactual accounts by referring to them by means of (modally) non-rigid designators: terms referring to different objects in different possible worlds. After all, it is common to refer to proofs, theories, and stories by means of definite descriptions, which, unless they are explicitly rigidified, can easily be interpreted as non-rigid. For example, it makes sense to say that Gödel’s proof of the first incompleteness theorem could have been shorter, and that the story of Cain and Abel could have involved different characters. For the same reason, it makes sense to say that the proof and the story could have been more or less beautiful.10 In the language of possible worlds, “Gödel’s proof of the incompleteness theorem” picks out different, albeit similar, proofs in different worlds, some more beautiful than others; likewise, “the story of Cain and Abel” picks out different, albeit similar, stories in different worlds, some more beautiful than others. On such an understanding of the designators involved, it is not trivially true that you would not have felt pleasure if the proof or the story had not been beautiful. For example, in some (distant) possible worlds, you are reading a story that is like the actual story of Cain and Abel—similar enough to be the story in a different possible world—and you are thrilled, even though the story you are reading is ludicrous and shallow. Still, in worlds that are closer to the actual world, you fail to be thrilled, which is enough to make the counterfactual conditional (“if the story had not been beautiful, you would not have felt pleasure”) true. So a counterfactual account of the causal power of abstract beauty may be feasible after all.

The need to interpret terms referring to abstract objects as non-rigid does not just arise in aesthetic contexts. For example, it is perfectly legitimate to wonder what would have happened if the story of Cain and Abel had been different in such-and-such non-aesthetic respects: would it have revealed a profound anthropological truth? Would it have been included in the Bible? A non-rigid interpretation of “the story of Cain and Abel” helps us to make sense of such what-if questions, regardless of whether they contain aesthetic terms or not. And, of course, a non-rigid interpretation of terms referring to concrete objects (“the first person to walk on the moon”) makes sense, too, so what we have here is a generalization rather than an ad hoc solution.

Of course, if none of these suggestions sound promising, there remains the option of restricting the claim about beauty’s causal efficacy to concrete objects. Such a restriction would not empty the claim of significance because, as the other objections make clear, there are also reasons for doubting that the beauty of concrete objects is causally efficacious.

One may object that, regardless of which theory of causation is preferred, the assumption that beauty is causally efficacious leads to a problem of systematic overdetermination. For if beauty causes, say, aesthetic pleasure, then what about the lower level “base” properties (colours, sounds) on which beauty supervenes? Would they not suffice to cause the pleasure in question?

Of course, the objection assumes that systematic overdetermination is always problematic, even when the causes are closely connected by some non-causal relation such as supervenience. (For an alternative view, see, for example, Hacker 1987, Shafer-Landau 2003, and Thomasson 2007.) Regardless of whether one accepts this assumption, there is another potential problem: the objection can easily be turned on its head. For if systematic overdetermination is problematic, and the choice is between beauty and its base properties, then why not opt for beauty instead? At least in some cases, aesthetic pleasure seems to depend counterfactually on beauty rather than on a conjunction of base properties. For example, a sensitive listener such as Liszt would probably have liked Mozart’s Requiem even if some of its notes had been different—Mozart’s talent would seem to guarantee this. But Liszt would probably not have liked it if it had not been beautiful. As a result, it is at least arguable that Liszt’s pleasure counterfactually depends on the Requiem’s beauty and not on the sequence of sounds that is its actual musical structure.11

So far, my response to the third objection has granted the assumption that there is overdetermination if we ascribe causal efficacy to both beauty and its base properties (in a particular case). In fact, within the framework of a counterfactual theory of causation, it is not even clear that we can speak of overdetermination in such a case, for it is unclear what it could mean for the base properties to “suffice to cause the pleasure”. It cannot mean that the base properties would have caused the pleasure in the absence of beauty. Such a scenario is ruled out by the relation of supervenience: necessarily, if the base properties for a supervening property are instantiated, then the supervening property is instantiated as well. But what else could “suffice to cause the pleasure” mean (again, within the context of a counterfactual theory)? If no viable option presents itself, perhaps it is better to regard beauty and its base properties (in a particular case) as joint causes or even as parts of a single cause, in which case there is no overdetermination.

One may object that, regardless of which theory of causation is preferred, the assumption that beauty is causally efficacious is in tension with a widely held platitude about beauty: namely, that experiencing the object (or a perceptual substitute of the object) is an ineliminable step in the process of coming to know that the object is beautiful. Note that this platitude does not imply that one must experience the object (or a perceptual substitute) for oneself; it does not commit one to the so-called Acquaintance Principle.12 (The principle entails the platitude but not vice versa.) What it does imply is that someone will have to have experienced the object (or a perceptual substitute) if someone is to acquire the knowledge that it is beautiful. In other words, the platitude is compatible with testimonial knowledge of beauty. It only requires the testimony to be ultimately traceable to a source who has experienced the object (or a perceptual substitute). Using Malcolm Budd’s (2007) terminology, one might paraphrase the platitude by saying that experience is the “canonical basis” for aesthetic attributions.

Now, the reasoning behind the fourth objection can be explained as follows. If beauty were causally efficacious, then, presumably, it would have a constellation of effects, just like any other causally efficacious property. However, if that were the case, then we would be able to tell whether something is beautiful by noticing the effects it has independently of it being experienced, and so our judgement would not have to be based on anyone’s experience, be it our own or someone else’s. Think, for example, of how a liquid’s acidity can be determined by means of a litmus test. Such a test can be administered and interpreted even if no one has ever been in direct perceptual contact with the liquid.

It seems that a concern of this sort underlies John Hyman’s view that beauty plays only a limited causal role—so limited, in fact, that he is happy to consider beauty a causally “inert” property, although, strictly speaking, that is an exaggeration. Beauty can be causally efficacious, according to Hyman, but only as a consequence of being experienced:

In other words, to unlock beauty’s causal potential, one first needs to experience beauty. In this way, experience is guaranteed to remain part of the process by which we come to know that something is beautiful. We cannot come to know it merely by observing beauty’s causal consequences because these consequences depend on the experience of beauty itself (see Figure 1 for an illustration).

The problem with Hyman’s view is that it leaves how we come to experience beauty in the first place a mystery. Because beauty’s causal power is supposedly unleashed only once it is perceived, and causes precede their effects, beauty itself cannot be the cause of our experience of beauty. As Hyman writes about the analogous case of colours: “the principle that colors are inert—that they cannot influence what happens except as a consequence of being seen—… implies that our perceptions cannot be explained by the colors of the objects we perceive” (Hyman 2006, 25; my italics). Hyman is unperturbed by this consequence of his view for the case of colours because “physics, chemistry, and physiology” provide an alternative explanation of how colour experiences are produced, for example, in terms of light reflectance properties (Hyman 2006, 20). However, it is doubtful whether our experiences of beauty can be explained in a similar way. Hyman is entirely silent on this question, which leaves how our experiences of beauty are to be explained on his view a mystery.

As an explanation of the necessity of experience, Hyman’s view also appears to be ad hoc in the light of the theories of causation mentioned earlier. For example, why would beauty not be able to cause our perception of it if it is regularly instantiated prior to our perceiving it, and, moreover, if our perception counterfactually depends on it? Hyman does not specify which condition deemed necessary and/or sufficient by either regularity or counterfactual theories of causation fails to be satisfied in the case of beauty.

A better explanation would grant beauty a causal role in our experience of beauty while, at the same time, keeping that role sufficiently confined so that no rival to experience-based knowledge of beauty can emerge. A proposal of this kind, illustrated by Figure 2, is to regard the experience of beauty as an effect of beauty that mediates all its other effects; in other words, whatever else beauty causes, it causes only via an experience of itself. Although the “cosmological role” thus assigned to beauty is wider than in Hyman’s theory—because beauty is supposed to cause experiences of beauty—it is still narrow (Wright 1994[1992]).14 Beauty cannot be assumed to make inanimate objects move from one place to another, for example, at least not in any direct manner.

Note that, in Figure 2, the arrow pointing directly from “Beauty” to “Feelings, actions” does not indicate that beauty would cause the feelings and actions even if there were no experience of beauty. The arrow is a sign of transitivity in the causal relation (or a sub-relation), not of a causal pathway bypassing our experience of beauty. Likewise, the arrow pointing from “Experience of beauty” to “Feelings, actions” does not indicate that the experience of beauty would cause the feelings and actions in the absence of beauty. Instead, what the arrows indicate is that beauty and the experience of beauty are both causes of the feelings and actions. In counterfactual terms, the occurrence of the feelings and actions depends counterfactually both on the presence of beauty and on the occurrence of the experience of beauty. In other words, the following counterfactuals are both true: (i) if the object had not been beautiful, then one would not have acted in a certain way; and (ii) if one had not experienced its beauty, then one would not have acted in a certain way. Of course, this kind of situation does not always obtain, but it obtains whenever beauty has causal consequences that go beyond the experience of beauty.

This last observation raises the question of how the experience of beauty differs from the feelings and actions that, according to Figures 1 and 2, are beauty’s other causal consequences. The answer depends on the case: that is, on which feelings and actions are caused. It also depends on how one conceives of the experience of beauty. For our present purposes, it suffices to conceive of this experience as one in which something is represented as beautiful (Zangwill 2005[2003]), or one in which it appears that something is beautiful (De Clercq 2019). The exact nature of the experience—for example, whether it is an affective state such as pleasure, as Hartmann (2014[1953]) claims—can be left undetermined. By labelling the consequences downstream of the experience of beauty as “feelings”, one does not commit oneself to the thesis that they are the first affective states caused by beauty.

The proposal under consideration retains at least two strengths of Hyman’s view while also doing better in several other respects. The respects in which the proposal does better are all tied to the fact that it allows beauty to cause the experience of beauty. This fact comes with three advantages. Firstly, it removes the mystery of how we come to perceive beauty. Secondly, it renders the proposal compatible with the hypothesis that some experiences of beauty counterfactually depend on the presence of beauty and are therefore—according to the counterfactual theory of causation—caused by it. Thirdly, one might be able to explain why there is proportionality between the degree to which the object is beautiful and the degree to which the experience of the object’s beauty is valuable: that is, why it is the case that the more beautiful the object is, the more valuable the experience is. The proportionality in question can be interpreted as the transference of a quality, namely the transference of a certain amount of value from beauty to its immediate effect. According to some theories (for example, Aronson 1971, Quine 1973, Fair 1979, Dowe 1992, Kistler 1998), transference of a (conserved) quantity such as energy or momentum is at least a necessary condition for causation. If these theories reveal something about causation in general, and not just about causation at the fundamental physical level, then what can be transferred should not be restricted to fundamental physical quantities but should at least in principle be allowed to include any transferable quality, such as value.15 As in the case of physical quantities, determining the quality would just be a matter of a posteriori investigation. My suggestion, illustrated by Figure 3, is that, in the case of beauty, the quality being transferred is a certain amount of intrinsic value.16 In support of this suggestion, one might cite the fact that experiencing beauty is actually found to be intrinsically rewarding.17

To recap: if we assume that beauty causes the experience of beauty, then we can explain why the value of the latter (how valuable the experience is) varies with the value of the former (how beautiful the object is). The reason is that, on a transference account of causation, causation involves the transference of some quality or other. Moreover, in the case of beauty, the quality being transferred can be taken to be a certain amount of value.

Obviously, this advantage of the proposal—one of the three advantages related to the assumption that the experience of beauty can be caused by beauty—hinges on a generalization of a theory of causation that is not universally accepted. Moreover, the proposal does not have this advantage if beauty is a disposition to cause a certain effect because the value of such a disposition derives from the effect rather than the other way around. For example, if a pill’s disposition to induce sleep is valuable, then that is because sleep is valuable; sleep is not valuable because the disposition to induce sleep is valuable. In other words, if beauty were a disposition, then one would see transference in the opposite direction, from the experience of beauty to beauty itself, contrary to what transference theories of causation predict. So the following seems to be a problematic combination of tenets: (i) beauty is a cause of our experience of beauty; (ii) beauty is a disposition; (iii) causation involves transference. However, because either (ii) or (iii) can be given up, we can still hold on to the belief that beauty is causally efficacious.

Up to this point, we have focused on the strengths associated with the fact that the proposal allows us to regard the relation between beauty and the experience of beauty as causal. However, as mentioned earlier, the proposal has at least two more strengths.

Firstly, as in Hyman’s view, the proposal implies the platitude that experience is an ineliminable step in the process of coming to know that something is beautiful. After all, according to this, any effect of beauty presupposes an experience of beauty as a joint cause of that effect. So if we come to know that something is beautiful indirectly, by observing one of its effects, or by observing effects of this effect (say, someone’s experienced-based testimony), and so on, then at least someone will have had an experience of beauty itself.

Secondly, and again as in Hyman’s view, the proposal explains how beauty moves: beauty moves by causing certain actions and feelings together with an experience of beauty itself.

For centuries, it has been recognized that beauty can move. My aim in this paper has been to understand how beauty moves. The hope was that it could make sense of Lessing’s suggestion that beauty moves in a causal way, for example, by causing us to have certain feelings. Four objections to the suggestion were considered, but none was found to be convincing in the light of how causation tends to be understood: that is, in terms of either nomological sufficiency or counterfactual dependence. At best, the objections showed, first, that one cannot simultaneously think of beauty as a non-natural property and as a cause backed by a lawlike regularity; and second, that one cannot simultaneously think of beauty as a disposition and as a cause transferring some quality—value—to an effect.

Moreover, in the discussion of Hyman’s view, it turned out that there is a positive reason for thinking that beauty is causally efficacious, not just once it has been experienced, as Hyman suggested, but even in bringing about the experience on which all the other effects of beauty depend.