 Broad thought that trying to explain or represent passage in terms of qualitative change was “doomed to failure.” A thing or substance, \(S\), can change in terms of a quality or property if property \(P_1\) and property \(P_2\) are determinates under a given determinable and \(S\) is \(P_1\) at \(t_1\) but \(P_2\) at \(t_2\). The passage of time, then, is to be thought of as an event’s having (say) the property of presentness and then immediately losing that property but gaining (and losing in turn) a long and possibly endless series of properties of the increasing degrees of pastness.