The Parts of Matter

Proposition 1: The parts into which matter was first divided were not round but angular.

Proof: All matter was in the beginning divided into equal and similar parts (Postulate).

Therefore (Ax. I and Prop. 2 Part 2) they were not round, but (Def. 4) angular. Q.E.D.

Proposition 2: The force that caused the particles of matter to move around their own centers, also brought them around that the angles of the particles would be worn away by collision with one another.

Proof: In the beginning, all matter was divided into equal (Postulate) and angular (Prop. I Part 3) parts.

Therefore, if their angles had not been worn away as soon as they began to move about their own centers, then of necessity (Ax. 2) the whole of matter would have had to occupy more space than when it was at rest. But this is absurd (Prop. 4 Part 2).

Therefore their angles were worn away as soon as they began to move. Q.E.D.