n of them. So if we say that an unsupported weight _must_
fall to the ground, we have included in the word "weight" the notion of
a downward strain. The proposition is really trifling and identical. It
merely announces that things which tend to fall to the ground tend to
fall to the ground, and that heavy things are heavy. So, when we have
called a thing a cause, we have defined it as that which involves an
effect, and if the effect did not follow, the title of cause would no
longer belong to the antecedent. But the necessity of this sequence is
merely verbal. We have never, in the presence of the antecedent, the
assurance that the title of cause will accrue to it. Our expectation is
empirical, and we feel and assert nothing in respect to the necessity of
the expected sequence.

[Sidenote: Mechanism and dialectic ulterior principles.]

A cause, in real life, means a justifying circumstance. We are
absolutely without insight into the machinery of causation, notably in
the commonest cases, like that of generation, nutrition, or the
operation of mind on matter. But we are familiar with the more notable
superficial conditions in each case, and the appearance in part of any
usual phenomenon makes us look for the rest of it. We do not ordinarily
expect virgins to bear children nor prophets to be fed by ravens nor
prayers to remove mountains; but we may believe any of these things at
the merest suggestion of fancy or report, without any warrant from
experience, so loose is the bond and so external the relation between
the terms most constantly associated. A quite unprecedented occurrence
will seem natural and intelligible enough if it falls in happily with
the current of our thoughts. Interesting and significant events,
however, are so rare and so dependent on mechanical conditions
irrelevant to their value, that we come at last to wonder at their
self-justified appearance apart from that cumbrous natural machinery,
and to call them marvels, miracles, and things to gape at. We come to
adopt scientific hypotheses, at least in certain provinces of our
thought, and we lose our primitive openness and simplicity of mind.
Then, with an unjustified haste, we assert that miracles are impossible,
i.e., that nothing interesting and fundamentally natural can happen
unless all the usual, though adventitious, _mise-en-scene_ has been
prepared behind the curtain.

The philosopher may eventually discover that such machinery is really
need