  It may be noted that Metochites deduces this proposition in two steps. First he says that it follows from Aristotle’s view—namely, (A) that movement is an asymmetrical relation between two contiguous entities, one of which causes movement and one of which is moved—(1) that for any movement, if the moving and the moved parts are disconnected, the movement will cease. Then he adds the further inference (2) that if the moving and the moved parts are identical, the moving part will not cease to cause movement. Since (2) clearly does not follow either from (A) or from (1), but does seem to follow from the converse of (1)—that for any movement, only if the moving and the moved parts are disconnected, the movement will cease—one may wonder whether Metochites may have fallen prey to the fallacia consequentis: if (if p then q) then (if not-p then not-q).