Explication I

Matter is the movable in space. That space which is itself movable is called material, or also relative space; that in which all motion must finally be thought (and which is therefore itself absolutely immovable) is called pure, or also absolute space.

Remark 1

Since in phoronomy nothing is to be at issue except motion, no other property is here ascribed to the subject of motion, namely, matter, aside from movability. It can itself so far, therefore, also be considered as a point, and one abstracts in phoronomy from all inner constitution, and therefore also from the quantity of the movable, and concerns oneself only with motion and what can be considered as quantity in motion (speed and direction). – If the expression “body” should nevertheless sometimes be used here, this is only to anticipate to some extent the application of the principles of phoronomy to the more determinate concepts of matter that are still to follow, so that the exposition may be less abstract and more comprehensible.

Remark 2

If I am to explicate the concept of matter, not through a predicate that belongs to it itself as object, but only by relation to that cognitive faculty in which the representation can first of all be given to me, then every object of the outer senses is matter, and this would be the merely metaphysical explication thereof.