 Broad is critical of this theory. To understand the nature of time, The Moving Spotlight Theory makes use of a spatial analogy. Such analogies “may be useful for some purposes, but it is clear that they explain nothing.” Firstly, Broad asks us to consider the successive lighting of presentness—now on one event and now on another, and so on. This is itself an event (or a series of events), “and ought therefore to be a part of the series of events, and not simply something that happens to the latter from outside” (1923, p. 60). If we suppose (as we seem compelled to) that it is not a part of the original series of events, we are launched on a vicious regress of time-dimensions. For then the successive lightning of later events would have to be conceived of as an event of the second order—happening in a time-dimension different from the original one formed by the series of first-order events. Secondly he presents a related line of reasoning—sometimes termed The Rate of Passage Argument: If anything moves, it must move with some determinate velocity. It will always be sensible to ask ‘How fast does it move?’ But since the series along which presentness is supposed to move is itself temporal, this question becomes: ‘how great a lapse of time 1 does presentness traverse in a unit of time 2?’ Again, a regress of time-dimensions is imminent. (Both of these arguments receive a clearer formulation and more extensive treatment in Broad  (1938).)[11]