Heidegger on Being Self-Concealing by Katherine Withy (Oxford University Press, 2022). ISBN 9780192859846

Unless one were to doubt that we know anything at all, we have knowledge of things, and these things exist. Arguably, the first move of idealism in philosophy is to take as paradigmatic this kind of overlap between what we know and what there is. It triggers an enquiry into what it means to know something and what that something, or anything, really,must be like for us to know it. In both epistemology and ontology, asking these sorts of questions is the approach of transcendental philosophy. In Kant’s formulation, we ask for the ‘conditions of possibility of the objects of experience’, of those things that exist and that we know. But things may go wrong, or stall. What if I presume that something exists, like the solution to a problem or the cause of something I see happening – but I cannot bring them clearly into view? In these cases, we know that there is something to be known, but don’t know how; we reach a limit of knowledge. Andwhat about the casewhere something completely unexpected happens? Here, something comes into being from beyond the limits of what we can know. But expected or not, once it is here, it no doubt exists, calling into question the notion that being and knowing are in principle co-extensive. The Kantian idealist’s response to these kinds of cases is that they don’t really matter. What counts is the good case, where cognition succeeds. Especially its very opposite, the case of something we don’t know and can’t even anticipate – why care? And how could we even think about that? Kate Withy’s book on the philosophy of Martin Heidegger shows that he did care, and it makes a good case that we should, too. The argument Withy sees Heidegger pursuing is a variation on the transcendental line of questioning, but with a crucial shift from clear success at knowing to limit cases. In fact, Heidegger takes these cases to provide an answer to the ontological question: for something to exist means for it to be, to some extent or in some respect, inaccessible to us. It is precisely the fact that things,