reality was sloppy, they are corrected; and they are replaced by others if it proves possible to adopt some new system, the which we may for some reasons prefer. Such analyses are mostly perceived by the expert scientific specialist as superfluous, stilted, at times even ridiculous. The situation changes however, when one of the casually employed terms is replaced by a sharper more accurate one, because the development of a particular science-branch commands it: Then energic protest and lamentations are voiced by those guilty of sloppy procedure with their own terms, fearing for their most holy possessions. In this howling the voices of other philosophers chime in who think themselves unable to do without yonder term, because they had so lined it up within their little treasure-trove of the "absolute", the "a priori", et cetera, that they had proclaimed it an irrevocable fundamental principle. The reader already conjectured that I am here particularly alluding to certain concepts of space and time and mechanics, which have been subjected to a modification through the theory of relativity. No one can take it away from the epistemologists that they paved the way here; at least in my own case I know that I have been propelled immensely, directly and indirectly, especially by Hume and Mach. I ask the reader to take into his hand the work of Mach: "The Science of Mechanics", and to contemplate his observations contained in its second chapter under parts VI. and VII. ("Newton's views of time, space, and motion." and "Discussion of Newton's view of time.") Here we find thoughts masterfully presented, which as of yet have not at all become the common property of physicists. These parts are also especially intriguing for the reason that they grow directly out of Newtonian passages, quoted verbatim. I provide here a selection of the choicest morsels:Newton: "Absolute, true, and mathematical time, of itself, and by its own nature, flows uniformly on, without regard to anything external. It is also called duration. Relative, apparent, and common time, is some sensible and external measure of absolute time (duration), estimated by the motions of bodies, whether accurate or inequable, and is commonly employed in of true time; as an hour, a day, a month, a year..." Mach: "... When we say a ThingA changes with time, we mean simply that the conditions that determine a ThingA depend on the conditions that determine another