Petri Ylikoski has very kindly reviewed my book. His review raises three interesting questions that I address here.
1. The relevance of epistemology to philosophy of science
Here is Ylikoski’s overarching assessment of the book:
I confess that I have always been doubtful of the relevance of analytical epistemology for philosophy of science. I think Khalifa's book demonstrates this with respect to theories of understanding. (I don't know if he himself would agree with this.) However, I am happy that somebody has worked through the literature.
To be honest, I don’t know if I agree with this either. I mean this quite literally: I have insufficient information to tell you whether I agree with Ylikoski’s claim that epistemology is irrelevant to philosophical theories of scientific understanding.
Allow me to explain. Give or take a few niceties, what I hoped to “demonstrate” in my book is that understanding is scientific knowledge of an explanation. Objections to that thesis come from both epistemologists and philosophers of science. I would have thought that objections are relevant to a thesis. That would entail the exact opposite of what Ylikoski claims: if successful, the book would have shown that epistemology is relevant to theories of scientific understanding.
Perhaps Ylikoski meant that none of the answers to these objections required extensive appeal to epistemology. However, as I argue in Chapter 2, an epistemological concept—safety—most sharply distinguishes my view from that of our fellow philosopher of science, Henk de Regt. It’s also difficult for me to see how my discussions of luck (in Chapter 7) and epistemic value (in Chapter 8) don’t involve some epistemological theorizing. So, I think that epistemology is relevant in this sense, too.
What can be gleaned from my book is that philosophers interested in what explanations are and what makes one explanation better than another ought not find understanding especially "deep." Alternatively stated:
- Philosophers would be better served by constructing a theory of understanding out of our best theories of explanation and explanatory power than the other way around.
Call this the (book’s main) debunking move. I stand by that claim, and if Ylikoski thinks that I’ve demonstrated that, then I’ve succeeded in the book’s overarching mission.
There is a certain sense in which the debunking move shows that epistemology is irrelevant to philosophy of science. In the philosophical division of labor, theories of explanation and of explanatory power fall mainly under the purview of philosophers of science. So, if the debunking move is sound, then there would be little left for epistemologists to contribute to a theory of understanding. I suspect that Ylikoski would welcome this result.
2. How much abstraction is too much?
Ylikoski’s main misgiving with my book is that my account of understanding is “too abstract… to consider things like (theoretical or practical) trade-offs between different dimensions of explanatory goodness, or various relations between explanations.” I am puzzled by this assessment. Ylikoski does not indicate how any of my arguments requires a story about these tradeoffs. Indeed, he voices no misgivings about any of the book’s arguments. This suggests that my account of explanation is not too abstract to perform the tasks to which I set it. Indeed, not only do these tradeoffs play no role in establishing a theory of understanding, the debunking move suggests that understanding should play no role in accounting for these tradeoffs. So, I fail to see why Ylikoski thinks that I should be addressing this issue.
3. The sense and varieties of understanding
The debunking move’s targets are not just epistemologists working on understanding—it also includes philosophers of science working on understanding. Since this seems to include some of Ylikoski's work, I suspect that he thinks this is a bridge too far. This suspicion is confirmed by the two issues he raises as loci for further philosophical theorizing about understanding:
(a) “It seems that some kind of sense (or feeling) of understanding has an important regulative role in our cognitive lives. It tells us when we need acquire more knowledge and when we have enough understanding to provide an explanation.”
(b) “We understand both scientific representations (theories, models, graphs, etc.) and phenomena with the help of those representations.” I only address the second of these kinds of understanding.
Ylikoski and I are just going to have disagree about how interesting these issues are. I admit that these probably signal differences in taste more than anything else.
Regarding (a): my view is that the most interesting way of determining whether we have enough understanding isn’t from the sense of understanding; it’s from the conversational context. That may have more to do with agents’ social statuses (as experts communicating to laypersons, for example) than anything going on in their heads. Because none of the book’s arguments hinged on developing these ideas, they were mentioned only in passing (especially in Chapters 1 and 6.) Furthermore, contra Ylikoski, I don’t see why the (philosophically interesting) sense of understanding isn’t reducible to beliefs about what one understands.
Regarding (b): When it comes to understanding, I can easily see why the explanations and predictions to which scientific representations contribute are of philosophical interest. By contrast, I do not see what’s philosophically interesting about scientific representations’ “legibility” or “user-friendliness.” Emily Sullivan and I briefly discuss our skepticism about legibility's epistemic value in our recent paper.
Despite these disagreements, I am grateful to Ylikoski for prompting me to state the debunking move a bit more explicitly than I did in the book.