  The objective is a foundation of physics from the operationalization of its
basic observables. We begin with classical and relativistic kinematics. Seizing
on a programmatic proposal by Heinrich Hertz we arrive via quantification of
energy-momentum at the equations of motion and the action functional. Finally
we present a relativistic revision of energy, momentum and inertial mass. The
goal is not primarily to change or improve the mathematical structure of
mechanics, but to gain a deeper physical understanding of mechanics like
Einstein with his gedanken experiments on relativistic kinematics. Starting
from undisputed measurement operations and natural principles the mathematical
formalism is only created and thus shown in a new light. This work is in the
same context as current efforts to the "foundation of quantum mechanics", just
with respect to the interpretation of the classical and relativistic
calculuses.
