Is there a problem of counterfactual philosophers?

by Massimo Pigliucci

This is my last report from the annual meeting of the American Philosophical Association. I had no idea what this session was going to be about, but the title was intriguing enough to make me skip a parallel one on Elliott Sober’s (very interesting, I read and reviewed it) book, Did Darwin Write the Origin Backwards?. Anyway, the session I actually attended was chaired by Jeff Sebo (NYU), the speaker was Nathan Ballantyne (Fordham), and the commentator was Adam Rosenfeld (Stony Brook). Warning: the below is going to be weird, and may even at times sound like a Monty Python version of what a philosophy talk is like...

Ballantyne began by pointing out that plenty of people who chose other professions could have instead done philosophy. And that of course there are philosophers who are dead but could have died later, especially in the case of those who died young, and could have contributed more to philosophical investigations.

We can think of plenty of epistemic counterfactuals, such as “if the student had studied for the exam he would have known the answer to the exam’s question.” The issue in which the author is interested is that in a number of nearby possible worlds some counterfactual philosopher might have come up with a “defeater” for certain arguments, that is with rational reasons to abandon a given position, reasons that are not available to us because the counterfactual in question is, well, counter-factual...

The problem, as stated by Ballantyne, is this: if a group of methodologically-friendly (e.g., analytical philosophers, if you are an analytic philosopher) counterfactual philosophers had scrutinized my best arguments for some proposition P and then shared their thoughts, I very likely would have defeaters for believing P. As a consequence, we should take seriously the possibility that some of our philosophical beliefs are not, in fact, rational or defensible. (I must say, I believe the latter even in the absence of counterfactual philosophers from nearby possible worlds...)

Ballantyne then entertained — in true philosophical fashion — a number of objections and replies to his central thesis. Here is a flavor, from his handout at the talk:

Objection: counterfactual philosophers might offer us defeaters, but they might not. So it’s doubtful that they would. Then why grant that they very likely would?

Reply: be imaginative.

Objection: wouldn’t methodologically-friendly counterfactual philosophers just agree with us?

Reply: it’s doubtful that the relevant methodological commitments alone guarantee agreement.

Objection: don’t the counterfactual philosophers cancel out?

Reply: consider a case where two sources deliver conflicting epistemic counterfactuals.

Objection: but I have conclusive, knockdown arguments.

Reply: maybe, but you’ll also need reasons to think they are.

And so on. Some of Ballantyne’s objection-reply pairs are a bit more complex, but you get the gist. Should we take this as a serious problem, or as a textbook example of how silly philosophy can get? Good question, and I’m inclined toward a middle ground view.

I can see Ballantyne’s logic, an example of thinking along the lines of possible-worlds logic, which has plaid a major role in certain quarters of analytic philosophy throughout the 20th century. There is an analogous of this problem in philosophy of science, sometimes referred to as the problem of unconceived alternatives. It is related to the issue of underdetermination of theory by the data, a staple of antirealism about scientific theories, and even of some science studies-type critiques of science.

For instance, Andrew Pickering famously proposed in his Constructing Quarks that fundamental physics could have taken a significantly different route from what it actually did during the 20th century, resulting in a picture of the world where the conceptual construct “quark” was not needed. Most physicists would likely react with outrage to this suggestion, and I am not endorsing it here, but it is a possibility, the likelihood of which depend on how necessary the role of certain theoretical entities really is in our views of the world. And of course it depends also on historical counterfactuals about what a different fundamental physics community might or might not have come up with.

The point is that this isn’t a silly possibility to be ruled out without engagement. Indeed, the issue — in philosophy — is related to my contention that philosophical investigations proceed by exploring the logical space relevant to a particular issue. Philosophy makes progress, in an important sense, by exploring spaces of logical possibilities, excluding certain options as inadequate, and working toward refining more promising ones. Think, for instance, how the original version of utilitarianism in ethics, proposed by Jeremy Bentham, was much less tenable than the more sophisticated views put forth by John Stuart Mill, and how those in turn have been significantly augmented by modern consequentialists like Peter Singer (again, this is not an endorsement of utilitarianism on my part, since I am more sympathetic to virtue ethics, but rather a good example of the general principle).

So, if a physicist says that there couldn’t possibly be a fundamental physics without quarks she is making a strong statement that the available empirical evidence constrains the logical space of possible physical theories so that one simply cannot avoid quarks in any good theory about the basic constituents of matter. Similarly, a philosopher who replies to Ballantyne along the lines of one of the objections above (say, counterfactual philosophers would likely agree with our current arguments and positions) is saying that modern philosophy has explored the fruitful regions of logical space concerning a number of issues to a high degree of accuracy, which is a position significantly more doubtful than the strong position held by our imaginary physicist concerning quarks. (I hasten to say that this conclusion is not arrived at because physics is a hard science and philosophy is fluff, but because the logical space in which philosophers typically move is much less constrained by empirical data than the space of theories about the actual world that physicists navigate. This could even be elaborated into an argument that philosophy is therefore much more difficult than physics, but I won’t go that far...)

All of the above said, one cannot possibly leave a session like the one I attended without having a nagging sensation that one has just witnessed an example of what Ladyman and Ross disparagingly refer to as “neo-Scholasticism.” You’ve got to admire the ingenuity of the argument, but at the end of the day you are left with the question: so what? Yes, counterfactual philosophers might have come up with defeaters for some positions that we think are solid, but guess what, counterfactual philosophers don’t exist, and we don’t have any way to access their counter-arguments, so all we can do is to keep doing what we always do: rely on actual philosophers to challenge our arguments, and to respond to the best of our ability to the objections real people actually throw at us. Philosophy, like science, is a human enterprise, and it advances within the constrains imposed by human epistemic limits. That said, as Ballantyne admonished, it’s always a good idea to remind ourselves that maybe a defeater (or a better theory in science) hasn’t been found not because it doesn’t exist, but simply because we have not (yet) stumbled upon it.