  The aim of this work is to provide a possible philosophical motivation to the
variational principles of physics in general and a possible way to unify the
axiomatizations of mechanics theories. The leitmotif of this work is a
dialectical view of the world: any smooth motion in nature is the consequence
of the interplay and dynamical balance between pairs of opposite elements of
the motion. We stress that the opposite property here differs from the common
sense of opposing elements (of conflicting appearance but of same nature) such
action/reaction forces between two bodies. The opposite elements here are
incompatible and mutual exclusive in nature, with contrasting and complementary
characteristics such as active/passive, disorder/order, curvature/flatness,
etc. The dynamical balance is defined by an invariant variational relationship
between all the pairs of opposite elements active in the considered motion.
From this idea, an axiomatization of quantum mechanics is proposed in addition
to the derivation of several existing variational principles of mechanics.
