By far the most common term in Professor Jeffner's paper is ‘understanding’, and it is clearly with understanding that he is primarily concerned. However, at the beginning of his paper he talks of understanding and explanation, and at least in the case of his third kind of reality he clearly sees understanding and explanation as intimately related. In this he is surely right. I myself would say that understanding is cognizing a manifold as a single whole in all its internal relationships, and this ties up with what Jeffner has to say about Gestalts on pp. 220–221. And explanation, as I hope to show, depends upon or presupposes the understanding that flows from the possession of a Gestalt. However, Jeffner adopts Hempel and Oppenheim's deductivist account of scientific explanation, and I believe this account to be fundamentally mistaken, and to have serious consequences for his argument. One does not achieve explanation merely by finding a set of empirically true premises from which a proposition expressing the explanandum can be deduced – if that were so one would explain Socrates' mortality by pointing out that everything snub-nosed is mortal, and that Socrates was snub-nosed. It is interesting, in this respect, to compare Hempel's account of explanation with that of Aristotle. There are substantial similarities between the two accounts, but there is one fundamental difference. Hempel insists that there can be no explanation unless events are connected in some way, and so rejects, for example, a mere sequential narrative as constituting an explanation.