De Rervm Natvra Constantivm Scientia, Principiis Et Affectionibvs Commvnibvs, Dispvtatio

LIV. We call the extension of parts in place "position," and the other "quantity." To which (to speak somewhat indirectly) it is a consequence that position and quantity are distinguished from each other really.

LV. Furthermore, having explained these two extensions of position and quantity, since we wanted the formal reason of quantity to be in extension, we have taken extension excluding the essential order to place. One part of this is in proximate potentiality, namely that which is aggregated from parts not needing the extension of another thing in order to be actually drawn apart from one another. The other is in remote potentiality, whose parts are of such a nature that they demand another extension as a necessary condition by which they are rendered distant. Quantity is the extension of parts in proximate potentiality; for it encompasses those parts to which it is immediately granted by nature that, with impediments removed and necessary things present, they are actually outside themselves and the parts of the substance by the medium of the extension of quantity. Whereby it happens that the extension of the substance is an extension in remote potentiality. And this much regarding extension; now we must deal with what parts these are, from which extension is joined, and then how they are coupled among themselves. And the discourse is about parts that are called "integrating," not "essential." For we are dealing with those from which quantity is constructed according to extension, and—what also needs noting—we will speak of the permanent, as we have done so far, not of the successive.

LVI. There were some who asserted that quantity is composed of indivisible Mathematical points. Although by their name they understood only indivisible parts, they still wanted the things which Mathematicians attribute to quantity by reason to agree with the same quantity in reality. For example, what Mathematicians say: that a body worked with perfect roundness admits no straight line; likewise, that in a triangle, several parallel lines cannot be drawn equal to the base from one side to another. Since these were to be referred to reason, they thought that in reality no straight line exists in a body endowed with absolute roundness, and they thought the sides of a triangle in reality differ from reason such that several equal parallel lines could not be drawn from the sides.