SPACE AND MOTION The topic for this lecture is the continuation of the task of explaining the construction of spaces as abstracts from the facts of nature.

It was noted at the close of the previous lecture that the question of congruence had not been considered, nor had the construction of a timeless space which should correlate the successive momentary spaces of a given time-system.

Furthermore it was also noted that there were many spatial abstractive elements which we had not yet defined.

We will first consider the definition of some of these abstractive elements, namely the definitions of solids, of areas, and of routes.

By a 'route' I mean a linear segment, whether straight or curved.