o stretch the meaning of the
term 'covering,' and to speak of one abstractive element 'covering'
another abstractive element. If we attempt in like manner to stretch the
term 'equal' in the sense of 'equal in abstractive force,' it is obvious
that an abstractive element can only be equal to itself. Thus an
abstractive element has a unique abstractive force and is the construct
from events which represents one definite intrinsic character which is
arrived at as a limit by the use of the principle of convergence to
simplicity by diminution of extent.

When an abstractive element A covers an abstractive element B, the
intrinsic character of A in a sense includes the intrinsic character
of B. It results that statements about the intrinsic character of B
are in a sense statements about the intrinsic character of A; but the
intrinsic character of A is more complex than that of B.

The abstractive elements form the fundamental elements of space and
time, and we now turn to the consideration of the properties involved in
the formation of special classes of such elements. In my last lecture I
have already investigated one class of abstractive elements, namely
moments. Each moment is a group of abstractive sets, and the events
which are members of these sets are all members of one family of
durations. The moments of one family form a temporal series; and,
allowing the existence of different families of moments, there will be
alternative temporal series in nature. Thus the method of extensive
abstraction explains the origin of temporal series in terms of the
immediate facts of experience and at the same time allows for the
existence of the alternative temporal series which are demanded by the
modern theory of electromagnetic relativity.

We now turn to space. The first thing to do is to get hold of the class
of abstractive elements which are in some sense the points of space.
Such an abstractive element must in some sense exhibit a convergence to
an absolute minimum of intrinsic character. Euclid has expressed for all
time the general idea of a point, as being without parts and without
magnitude. It is this character of being an absolute minimum which we
want to get at and to express in terms of the extrinsic characters of
the abstractive sets which make up a point. Furthermore, points which
are thus arrived at represent the ideal of events without any extension,
though there are in fact no such entities as these ideal events. T