Note 132:4 — Chapter V

The reader is referred to Mr. Bertrand Russell's chapters on matter and motion in his Principles of Mathematics, Vol. I. Material particles he defines as "many-one relations of all times to some places, or of all terms of a continuous one-dimensional series t to some terms of a continuous three-dimensional series s." Similarly, "when different times, throughout any period however short, are correlated with different places, there is motion; when different times, throughout some period however short, are all correlated with the same place, there is rest." Op. cit., p. 473.