 Natorp’s treatment, though scarcely six pages is more detailed (1910: 399–404). In revisionist fashion, the “Minkowski (sic) principle of relativity” was welcomed as a more consistent (as avoiding Newtonian absolutism) carrying through of the distinction between transcendentally ideal, purely mathematical, concepts of space and time and the relative physical measures of space and time. The relativization of time measurements, in particular, showed that Kant, once shorn of the psychologistic error of pure intuition, correctly maintained that time is not an object of perception. Natorp further alleged that from this relativization it followed that events are ordered, not in relation to an absolute time, but only as lawfully determined phenomena in mutual temporal relation to one another, a version of Leibnizian relationism. Similarly, the light postulate had a two-fold significance within the Marburg conception of natural science. On the one hand, the uniformity of the velocity of light, deemed an empirical presupposition of all space- and time-measurements, reminded that absolute determinations of these measures, unattainable in empirical natural science, would require a correspondingly absolute bound. Furthermore, as an upper limiting velocity for physical processes, including gravitational force, the light postulate eliminated the “mysterious absolutism” of Newtonian action-at-a-distance. Natorp regarded the requirement of invariance of laws of nature with respect to the Lorentz transformations as “perhaps the most important result of Minkowski’s investigation”. However, little more is said about this, and there is some confusion regarding these transformations and the Galilean ones they supersede; the former are seen as a