The objective of this monograph is to present some methodological
foundations of theoretical mechanics that are recommendable to graduate
students prior to, or jointly with, the study of more advanced topics
such as statistical mechanics, thermodynamics, and elementary particle
physics. A program of this nature is inevitably centered on the
methodological foundations for Newtonian systems, with particular
reference to the central equations of our theories, that is, Lagrange's
and Hamilton's equations. This program, realized through a study of the
analytic representations in terms of Lagrange's and Hamilton's equations
of generally nonconservative Newtonian systems (namely, systems with
Newtonian forces not necessarily derivable from a potential function),
falls within the context of the so-called Inverse Problem, and consists
of three major aspects: l. The study of the necessary and sufficient
conditions for the existence of a Lagrangian or Hamiltonian
representation of given equations of motion with arbitrary forces; 2.
The identification of the methods for the construction of a Lagrangian
or Hamiltonian from given equations of motion verifying conditions 1;
and 3 The analysis of the significance of the underlying methodology for
other aspects of Newtonian Mechanics, e. g., transformation theory,
symmetries, and first integrals for nonconservative Newtonian systems.
This first volume is devoted to the foundations of the Inverse Problem,
with particular reference to aspects I and 2.