method of unity—preferring theories that are more unified—is a close cousin of the method of simplicity, though I leave that argument for another time.
8 Copernicus’ theory also involved epicycles and it is not clear from the historical record how many epicycles he added to his theory. But treat this as a thought experiment if you like: Imagine that Ptolemy’s theory did achieve greater fit with the data than Copernicus’, but only by postulating hundreds more epicycles. It would still be evaluated as an epistemically worse theory because of its significant lack of simplicity. I’ll explore this example in more detail in chapter 4.
9 I have focused on simplicity thus far, but this should not be read as giving a privileged place to simplicity. I am not suggesting that simplicity and beauty are identical, nor do I think that all judgments of beauty are judgments of simplicity. But I will argue (mainly in chapter 4) that simplicity is one particular species of beauty (alongside others on this list: coherence, unity, elegance, and so on). That is, simplicity is one type of how a thing can be beautiful. Some have been concerned to argue that judgments of beauty in math and science are not merely judgments of simplicity; see Inglis and Aberdein (2014) and Todd (2008). Such arguments will not be threatening to my view, since I am not identifying beauty with simplicity, but only simplicity as one type of beauty. I will also argue in detail (mainly in chapter 3) that coherence, like simplicity, is one particular species of beauty. But I am not claiming that either of these are identical with beauty: beauty will be a broader category than either of these. Obviously, making these claims will require at least a mid-level account of beauty, which I will develop in chapter 2.
10 For discussions of the role of aesthetic judgment in science, see Bigu (2014), Chandrasekhar (1987), Curtin (1982), Elgin (2017), Engler (1990), Kivy (1991), Kosso (2002), Martin (1989), McAllister (1989 and 1999), O’Loughlin and McCallum (2019), Scorzato (2016), Thagard (2005), Todd (2008), Weyl (1952), and Zemach (1986).
11 This adage is often attributed to Plato. Although is not found word-for-word in his work, it does obviously fit with his thought.
Beauty is in the eye of the beholder, so they say.1 A great many readers—philosophers and lay readers alike—will feel the force of this aphorism and think it is an insuperable barrier to any serious thesis about beauty.2 The aphorism is usually meant as a shorthand way of saying that beauty is thoroughly relative.3 This means that the truth values of claims about beauty are utterly relative to being claimed: when a claim about beauty is made, it is thereby true. If this is true, then claims about beauty are indeed idle. Claims about beauty will only be true or false in virtue of whether they are claimed or not and thus cannot be advanced as though they were really true.4 For example, the truth value of a claim like “This theory is more beautiful than that one” will be true if that claim is asserted and false if that claim is denied. Thus, that statement could not be used as part of a serious argument. Any argument that applied my thesis will be plagued by this problem. For example:
Premise 1—Beauty is relevant to whether a theory is true.
Premise 2—Thstyseory T is more beautiful than its competitors.
Conclusion—Therefore, I have reason to believe that Theory T is true.
If relativism about beauty is true, then Premise 2 in this argument cannot be advanced as though it were really true. My thesis would thus be, at best, idle and, at worst, false. To advance my thesis that beauty is relevant to whether a theory is true, I must disambiguate the aphorism and argue that beauty is not thoroughly relative. That is what I will do in this chapter.
Arguments for Relativism from the Aphorism
The first argument against this line of thought is straightforward: there is something highly dubious about doing philosophy by aphorism. Analytical philosophers are not usually in the business of accepting an aphorism from received wisdom as an answer to a philosophical question. For example, if we ask the question “What is the nature of knowledge?” answering “Knowledge is power” is not satisfying. We want to know what the aphorism means, which theory of the phenomenon it comes from, and—most importantly—whether it is true. Our question is whether beauty is relative or not. Answering “It is relative because beauty is in the eye of the beholder” is not a satisfying answer. Citing the aphorism of “beauty is in the eye of the beholder” should only raise further questions: What does the aphorism mean? Which theory of beauty is it based on? Is it true? If “beauty is in the eye of the beholder” simply means that beauty is thoroughly relative, then it obviously cannot be offered as a response to the question “Is beauty thoroughly relative?” Such a response is blatantly question-begging and can be dismissed out of hand. We need an argument as to whether beauty is thoroughly relative or not, not simply an aphorism that asserts that it is. If, on the other hand, the aphorism does not simply mean that beauty is thoroughly relative but is meant to support the claim that beauty is thoroughly relative, then we need to know what the aphorism means and what the argument is. I’ll next try to reconstruct what the aphorism might mean and to see whether it can generate any non-question-begging arguments about beauty being relative.
The aphorism says that beauty is in the eye of the beholder. Most literally, this tells us “where” beauty is located: it’s in the eye of the beholder. The eye is a perceptual organ and the beholder is one who is beholding, one who is perceiving. Thus, taken literally, the aphorism means something like beauty is located in the perceptual apparatus of a perceiver. This seems to tell us that beauty is bound up with perceiving and perceivers. If it is located in the perceptual apparatus of a perceiver, then if there were no such perceptual apparatus (and hence no perceivers) then there would be no place for beauty to “live.” So beauty can only exist if there are perceivers. Does this entail that beauty is thoroughly relative, that the truth values of claims about beauty are true only in virtue of being claimed? No. For a phenomenon to be thoroughly relative is a fact about the structure of its truth value. For a phenomenon to depend for its existence on perceivers is a fact about where in nature it is found. There are plenty of phenomena that are “located in perceivers”—their existence depends on the existence of perceivers—which are nevertheless not thoroughly relative. Most philosophical theories of color hold that color has this structure: color is not to be literally found in an object itself but is instead found in the perceiver perceiving the object.5 But this does not thereby entail that color is thoroughly relative. Perception itself is a more general and powerful example: by definition perception can only exist in perceivers, but this does not entail that all perception is thoroughly relative.
If the aphorism only literally says something about where beauty is located, why do so many move to thinking that it entails that beauty is thoroughly relative? My diagnosis is a confusion of the terms “subjective” and “relative.” Subjective means “of, or relating to, a subject.” Relative means “not universal, true only in light of something arbitrary.” These words are sometimes used interchangeably, but they should not be. For a thing to be of, or related to, a subject is for it to be “in” or “of” perceivers, for its existence to depend on the existence of subjects, perceivers. But for a thing to be relative is not about “where” it is, but about the structure of its truth value.6 Once we’re clear about these words, it should be obvious that color and perception are subjective—they are of, or related to, a subject—but not relative—there are nonarbitrary truth values of colors and perceptions. Even more generally, subjectivity itself is (by definition) subjective but not relative. Even if it is true that beauty is subjective—it is “in” perceivers—this does not entail that beauty is relative—that claims about beauty are only true in light of something arbitrary.
