All bodies agree in certain respects.
Proof .-- All bodies agree in the fact, that they involve the conception of one and the same attribute (II., Def.

i.).
Further, in the fact that they may be moved less or more quickly, and may be absolutely in motion or at rest.
LEMMA III.

A body in motion or at rest must be determined to motion or rest by another body, which other body has been determined to motion or rest by a third body, and that third again by a fourth, and so on to infinity.
Proof .-- Bodies are individual things (II., Def.

i.), which (Lemma I.) are distinguished one from the other in respect to motion and rest; thus (I.xxviii.) each must necessarily be determined to motion or rest by another individual thing, namely (II.

vi.), by another body, which other body is also (Ax.