will continue to denote the fundamental relation of extension from which all the relations here considered are derived.
[CHAPTER IX]
DURATIONS, MOMENTS AND TIME-SYSTEMS
[33. Antiprimes, Durations and Moments]. 33.1 Among the constants of externality discussed in [Part II] was the reference of events to durations which are, in a sense, complete wholes of nature. A duration has thus in some sense an unlimited extension, though it is bounded in its temporal extent. Although we have not yet in our investigation of
distinguished between spatial and temporal extension, durations can nevertheless be defined in terms of
by this unlimited aspect of their extents. Namely, we assume that there are no other events with the same unlimited property. Accordingly, any abstractive class which is composed purely of durations can only be covered by abstractive classes which also are composed purely of durations.
33.2 An abstractive class
is called an 'absolute antiprime' when