 At first sight, this looks like an early expression of explanatory empiricism: a refusal to make inferences to things that cannot be observed. But even leaving aside the fact that “the things in the sky” are not strictly unobservable, the same work also also speaks of discovering facts about what is inside the body “from evident things outside [the body]” (AM 22.3). In particular, it argues, we can draw conclusions about the body’s internal organs by noting the behaviour of different kinds of observable objects: those that are solid, stretched, spongy, porous, and so on. (The reasoning here is by way of analogy, a common practice among the earliest Greek thinkers [Lloyd 1992: 254–55; Allen 2001: 10–11].) This seems inconsistent with explanatory empiricism, since it justifies inferences from what can be observed to what is (at least in practice) unobservable.