l system
whatever, are all functions of time and of each other, and of nothing
else. In other words, we have to deal, in this mode of regarding
things, with a definite and completely determinate world, to which
prediction may confidently be applied.

But this determinateness is got by refusing to contemplate anything
outside a certain scheme: it is an internal truth within the assigned
boundaries, and is quite consistent with psychical interference
and indeterminateness, as soon as those boundaries are ignored;
determinateness is not part of the _essence_ of dynamical doctrine,
it is arrived at by the tacit assumption that no undynamical or
hyperdynamical agencies exist: in short, by that process of abstraction
which is invariably necessary for simplicity, and indeed for
possibility, of methodical human treatment. Everyone engaged in
scientific research is aware that if exuberant charwomen, or
intelligent but mischievous students (who for the moment may be taken
to represent life and mind respectively) are admitted into a laboratory
and given full scope for their activities, the subsequent scientific
results--though still, no doubt, in some strained sense, concordant
with law and order--are apt to be too complicated for investigation;
wherefore there is usually an endeavour to exclude these incalculable
influences, and to make a tacit assumption that they have not been let
in.

There is a similar tacit assumption in treatises on Physics and
Chemistry; viz., that the laws of automatic nature shall be allowed
unrestricted and unaided play, that nothing shall intervene in any
operation from start to finish save mechanical sequent and
antecedent,--that it is permissible in fact to exercise abstraction, as
usual, to the exclusion of agents not necessarily connected with the
problem, and not contemplated by the equations.

In text-books of Dynamics and in treatises of Natural Philosophy that
is a perfectly legitimate procedure;[4] but when later on we come to
philosophise, and to deal with the universe as a whole, we must forgo
the ingrained habit of abstraction, and must remember that for a
_complete_ treatment _nothing_ must permanently be ignored. So if
life and mind and will, and curiosity and mischief and folly, and greed
and fraud and malice, and a whole catalogue of attributes and things
not contemplated in Natural Philosophy--if these are known to have any
real existence in the larger world of total experience, an