Do Philosophers Feel Bad For You?

A theoretical physicist, Sabine Hossenfelder, and a philosopher, Philip Goff, recently got into a Twitter spat about electrons. Hossenfelder advanced the view that physics was instrumental—simply a way of talking that uses highly abstract terms to make predictions about the world. But, she argued, there was nothing more that the physicist needed to say about the existence of entities such as electrons in order to make use of their mathematical properties. Goff then argued that although there was nothing more the physicist needed to say about electrons to get on with the business of doing physics, there was surely something more that the theoretical physicist was committed to—namely, that the entities their theories referred to existed. Goff speculated that because Sabine’s theories refer to electrons, they entail a commitment to them existing.

Of course, being told what you’re really saying never goes down well, especially not on Twitter. Sabine accused Goff of mischaracterizing her position. Goff appeared to pull rank. Sabine claimed Goff had tried to ridicule her. Goff offered an apology and claimed there had been a misunderstanding. Eventually, they let it go and their exchange was entered into the big book of Twitter grudges. But then, from the woodwork, scientific twitterers emerged to rally around Hossenfelder and proclaim their skepticism about philosophy. Memes like this one floated around, depicting a scruffy philosopher who looks up at a well-groomed scientist and says “I feel bad for you,” before the scientist responds, “I don’t think about you at all.”

Hossenfelder does think about philosophy (there are many “intelligent and insightful philosophers of science,” she said, although I suspect she doesn’t count Goff among them). Given that Hossenfelder isn’t a scientist who thinks they have nothing to learn from philosophers of science, it’s therefore an open question as to which philosopher best represents her view. In what follows, I’ll try to make clear Hossenfelder’s philosophical position. Through this endeavor, we begin to see why Twitter is not the best public forum for philosophers to go toe-to-toe with scientists, as well as why philosophers feel bad for scientists who don’t think about philosophers at all.

At first glance, Hossenfelder’s position seems best put by this tweet: “You don’t need maths to see that assuming the existence of other universes is unscientific. All you need is to understand that assuming the existence of something you cannot observe is unnecessary to explain anything you can observe.” This seems like a philosophical position called ‘instrumentalism.’ Roughly speaking, instrumentalism maintains that entities such as electrons are posited by scientists to better understand observable phenomena. On this view, electrons are, in some loose sense, ‘instruments’—theoretical physicists put ‘electrons’ to various uses. For example, Sabine’s theorizing results in some predictive empirical successes, and, as such, although it’s as if electrons exist because we can’t observe them, we don’t need to ask whether they really exist. As Hossenfelder put it: “science cannot make any statements about the existence of something we can’t observe, may that be gods or other universes.”

But is Hossenfelder really committed to this view? Consider the following exchange: Goff says: “We can’t observe electrons, but they’re part of a good theoretical explanation of what we can observe. What am I missing?”. To this, Hossenfelder replies: “If you mean to say that “electrons” is not an observable, then you’re right.” So far this seems pretty instrumentalist. Electrons are not observable and yet they feature in good theoretical explanations. But the trouble then comes when Hossenfelder is asked what exactly she means when she says electrons are not an observable. Does she mean that we have no direct acquaintance with electrons? This seems like a good place to start. Electrons cannot be observed no matter how powerful the microscope (their radius is basically size 0), and thus we are observationally acquainted with them only indirectly by way of their interactions with other objects or as patterns on a computer screen. But if this is what she means, then how can she say in the same breath that the existence of other universes is unscientific? After all, some multiverse theories allow for causal contact between universes—we may be indirectly acquainted with them and come to detect them just like with electrons.

Puzzled by Hossenfelder’s insistence that positing electrons is scientific but positing multiverses isn’t, Goff might have asked: what, if anything, she did take to exist (or, to use a philosopher’s turn of phrase, what her ‘ontological commitments’ were)? Tables? Yes. Ghosts? No. Numbers? Here I imagine Hossenfelder shrugging—this last question is surely one for the philosophers. A more productive philosophical conversation between Goff and Hossenfelder could have asked these questions rather than press her on what she meant by “observable.” At least some of Hossenfelder’s ontological commitments could have been made clear—that is, she believes in the existence of tables and not in the existence of ghosts. If Hossenfelder thinks herself a good naturalist and a champion of the sciences, then surely no matter her scruples about existence questions she would accept “tables” as irreducible posits if they play an indispensable explanatory role in scientific theorizing. If Hossenfelder wouldn’t accept this, then it seems the expressive power of obviously scientific theories (albeit not of theoretical physics, but then science is not merely theoretical physics), would be severely limited. Suddenly, theorizing about tables would require scientists to theorize about tables’ mereological parts.

Let’s suppose Hossenfelder is not ungenerous to her colleagues down the hall. But then, assuming Hossenfelder doesn’t deny the existence of the referent ‘table’ because scientists productively using the term implies its existence, Goff can simply add ‘electrons’ and ‘multiverses’ to his list of existence questions. Put another way, Goff can regiment his and Hossenfelder’s ontological commitments (in short, translate their terms into a formal language) and get clear on their common existential assumptions.

How might Hossenfelder answer? Suppose that Goff affirms and Hossenfelder denies the existence of electrons. Well, if Goff can show that his affirming their existence merely involves a commitment to the same sort of expressive power as Hossenfelder doubtlessly affords other scientific theories (for example, theories that explain how wooden tables react in, say, volcanic lava), then to be consistent Hossenfelder should accept that electrons exist because they are indispensable to her theorizing as well. Goff is then well-placed to ask Hossenfelder how she can consistently maintain the position that multiverses are unscientific if they are similarly indispensable to another’s theorizing.

I doubt the conversation would have gone this way. Firstly, because asking a scientist whether they believe in the existence of tables and ghosts comes across as patronizing (especially if the scientist in question already suspects their leg is being peed on). Secondly, because Twitter does not allow philosophers the time to justify retreating to questions such as whether tables or ghosts exist. The comment section is full of people ready to dismiss this as unserious—the philosopher has already been ‘discredited’ by way of ad hominem before they can reach those who might be reached. Moreover, Twitter-damage cannot be undone by pointing to ‘scientism’ as a culprit, as Goff did, not just because it’s asking a lot for people to do their own research, but because the further into a comment thread you go the less traction your tweet gets. On Twitter, clarifications by way of response go the same way as newspapers apologizing for misreporting—the damage has already been done.

Thirdly, and most importantly, Twitter’s overwhelming comment-thread structure (for those not on Twitter—think fractal canopy) invariably results in key tweets with subtle nuances getting lost in the thicket. Hossenfelder and Goff’s online exchange is a prime example of this because Hossenfelder’s view is not actually instrumentalist. In a telling tweet, she claimed that “science works regardless of what philosophical position you hold about it […] is not a philosophical position.” Maybe Hossenfelder isn’t interested in making existence claims at all then, and no matter what common epistemological ground Goff might have established through a strategy of regimentation, Hossenfelder’s response would have been to say that existence questions are just not scientific questions. This interpretation has Hossenfelder say that introducing “there is” into any list of things (tables, chairs, ghosts, electrons, multiverses) carries with it an existential commitment that it’s not the business of scientists to involve themselves with. In her capacity as a scientist in the context of their Twitter row, her position really was “I don’t think about you at all”—electron-talk is useful for my predictive purposes, so I’ll go on with my theorizing thank you very much!

Hossenfelder was right, therefore, when she said that she was being misunderstood as an instrumentalist. But she was wrong to say her position was not philosophical. After all, there are philosophers who share in the spirit of the (metaphysically) ontologically averse. Some philosophers think that her way of rejecting existential questions is a perfectly legitimate response. These are the Carnapians. For Carnapians, science is the business of making predictions, and needn’t concern itself with the vagueness that comes along with natural language claims about what really “exists.”

Whether Hossenfelder wants to defend this philosophical position is not so clear. Many branches of science besides theoretical physics use vague terms (terms like “table”), so what then must we infer about the other branches of science? What of the chemist? What of the astronomer? It seems the question of what water is, or what dark matter is, comes back into view. Whether Hossenfelder takes up this philosophical position, however, is not the interesting question. The interesting question is the philosophical one—whether a deflationary position on existence claims can be successfully argued for. After all, if Hossenfelder’s own scientific predictions stop being correct, then the philosophical question can be asked—in virtue of what did her theories stop making successful predictions? Perhaps something like the world? Carnapians have their responses ready. And so the (really quite old now) conversation goes on.

Philosophical debate continues irrespective of whether you are aware of it or stick around for it. Usually, a position staked out as non-philosophical has already been defended by philosophers at some stage. Maybe it’s in this sense that the philosophers feel bad for scientists. Although—depending on the debate, and especially depending on the forum of the debate—maybe scientists are still having the last laugh.

Jack Morgan Jones

Jack Morgan Jones is a PhD candidate in Philosophy at the University of Manchester. He works on questions of truth, rationality, and the philosophy of history.