e a force in operation,
and, as a physicist, cannot examine its genesis. The physical or the
metaphysical method of inquiry is valid only so long as restricted to
physical or metaphysical processes: a mixture of the two methods will
give results satisfactory neither to science nor to philosophy. As logic
furnishes no criterion by which to test the absolute truth of
propositions, but deals wholly with conclusions drawn from given
premises, so science furnishes no data by which to determine the
absolute genesis of force, but restricts its enquiries to the phenomena
resulting from a force given. For the student of physical science cause
and effect is only the transference of a given and determined force from
one material form to another. If this idea is to be traced further, it
must be studied outside the limits of physics. This study belongs to
metaphysics.

Now, if physical science does not deal with the origin of the initial
force, but assumes at the outset its presence, no more does it fall
within its province to examine into the origin of the increments which
give to physical forms that variety which renders science possible.
Science deals with results, not antecedents; and after having determined
results, it is not authorized to affirm that one species has produced
another by evolution, or has produced it at all. If there are agreements
between different organisms by which they are brought into relation,
there are also differences by which they are discriminated, and these
differences imply increments of force; and to assert that one organism
has evolved another is to determine not merely the presence of this new
increment, but also to determine its origin. Scientific investigation
deals with phenomena which give evidence to the senses of a
_transference_ of force from one form or from one manifestation to
another. Transference is not increase--an effect can be no more than the
evolution of what was potentially present in the cause; it cannot add to
it. The origin of the force must be investigated according to
intellectual laws.

It has been argued that a Supreme Intelligence in manifesting his
thought will, according to the necessary laws of rational activity, pass
from the universal and general to the particular and individual, or from
concepts involving few attributes to those involving these and others;
and that these steps in the rational process must be represented in a
corresponding physical series; and th