In 1922, Kottler put forward the program to remove the gravitational potential, the metric of spacetime, from the fundamental equations in physics as far as possible. He successfully applied this idea to Newton's gravitostatics and to Maxwell's electrodynamics, where Kottler recast the field equations in premetric form and specified a metric-dependent constitutive law. We will discuss the basics of the premetric approach and some of its beautiful consequences, like the division of universal constants into two classes. We show that classical * Based on an invited talk given at the Annual Meeting of the German Physical Society (DPG) in Berlin on 20 March 2015, "Working Group on Philosophy of Physics (AGPhil)". We sincerely thank Dennis Lehmkuhl (Wuppertal, now Pasadena) and his co-organizers Meinard Kuhlmann (Mainz) and Wolfgang Pietsch (Munich) [92] for the invitation. In the present version, we appreciably enriched our text by adding more formalism. We apologize to the philosophers for any inconvenience. A short version of this paper will be submitted to the International Journal of Modern Physics D.