 As noted when discussing positional motion, Avicenna follows the Aristotelian tradition and identifies the technical definition of place (Gk. topos, Ar. makān) with “the surface that is the extremity of the containing body” (Avicenna, [Ph], 2.9 [1]). The general structure of his argumentation for this thesis involves showing that all other candidates for what place might be are wanting in some way. To this end, Avicenna provides us with, as it were, the logical space for an account of place (Avicenna, [Ph], 2.6 [2]). Place can be either intrinsic or extrinsic to body, that is, essential or accidental to it. If place is intrinsic to a body, then it is either (1) the matter or (2) the form of the body, whereas if it is extrinsic, then the place is either (3) what the body exactly encompasses, that is, an interval (buʿd) or (4) what exactly encompasses the body, that is, the surface that is the extremity of the containing  body.[10]  Avicenna quickly eliminates (1) and (2). That is because a body can change with respect to place, that is, depart from one place to another, whereas a body cannot depart from either its matter or form without undergoing generation and corruption. Hence only (3) and (4) are truly live options. Account (4) is just the Aristotelian one, which Avicenna himself prefers. As for (3), namely that a body’s place is the interval it occupies, Avicenna believes that it ultimately stands or falls with whether a void (khalāʾ), an empty interval, is possible. Avicenna dedicates a long chapter (Avicenna, [Ph], 2.8) to showing that a void is impossible. If his argument there is successful, then (4), namely, place is the innermost limit of the containing body, remains the only viable definition of place. 