n of the laws of dynamics, and in full
correspondence with both the conservation of energy and the
conservation of momentum.

That is where I part company with Professor James Ward in the second
volume of _Naturalism and Agnosticism_; with whom nevertheless on many
broad issues I find myself in fair agreement. Those who find a real
antinomy between "mechanism and morals" must either throw overboard the
possibility of interference or guidance or willed action altogether,
which is one alternative, or must assume that the laws of Physics are
only approximate and untrustworthy, which is the other alternative--the
alternative apparently favoured by Professor James Ward. I wish to
argue that neither of these alternatives is necessary, and that there
is a third or middle course of proverbial safety: all that is necessary
is to realise and admit that the laws of Physical Science are
_incomplete_, when regarded as a formulation and philosophical summary
of the universe in general. No Laplacian calculator can be supplied
with all the data.

On a stagnant and inactive world life would admittedly be powerless: it
could only make dry bones stir in such a world if itself were a form of
energy; I do not suppose for a moment that it could be incarnated on
such a world; it is only potent where inorganic energy is mechanically
"available"--to use Lord Kelvin's term,--that is to say, is either
potentially or actually in process of transfer and transformation. In
other words, life can generate no trace of energy, it can only guide
its transmutations.

It has gradually dawned upon me that the reason why Philosophers who
are well acquainted with Physical or Dynamical Science are apt to fall
into the error of supposing that mental and vital interference with the
material world is impossible, in spite of their clamorous experience to
the contrary (or else, on the strength of that experience, to conceive
that there is something the matter with the formulation of physical and
dynamical laws), is because all such interference is naturally and
necessarily excluded from scientific methods and treatises.

In pure Mechanics, "force" is treated as a function of configuration
and momentum: the positions, the velocities, and the accelerations of a
conservative system depend solely on each other, on initial conditions,
and on mass; or, if we choose so to express it, the co-ordinates, the
momenta, and the kinetic energies, of the parts of any dynamica