 Geometrical propositions, too, are inferred from premises which themselves have real content. Such premises—that, for instance, we can draw a straight line connecting any two single points—are not mere verbal propositions. Indeed, Mill claims, such premises are not strictly even true of the real space we encounter in experience: neither perfectly single points, nor perfectly straight lines exist in nature. These are rather idealizations of that space—but idealizations which are based on principles that could only be known by inductive generalization of our observations. The same holds for the results of geometric reasoning (System, VII:  224ff.).[3]