 We saw, briefly, in  section 3.3.1,  why Wiggins and Ayers think as they do. Although van Inwagen’s position is different from both, his reasons for thinking that the concept of a complex body is, of its own, an inadequate concept, are consistent with Wiggins’s claim that the idea is too determinable to function in its own right. Van Inwagen, therefore, more directly challenges Ayers. (For a brief discussion of van Inwagen’s argument, see  section 3.4  below.)