is not all; for the B that gives rise to C is never
merely the effect of A; it involves something further. Take such a
simple case as the motion of the earth round the sun (neglecting all
other conditions, the other planets, etc.); and let the earth's
motion at three successive moments be A B C: A is not the whole cause of
B in velocity and direction; we must add relation to the sun, say x. But
then, again, the cause of C will not be merely Bx, for the relation to
the sun will have altered; so that we must represent it as Bx'. The
series, therefore, is Ax Bx' C. What is called a "remote cause" is,
therefore, doubly conditional; first, because it supposes an intervening
cause; and secondly, because it only in part determines the conditions
that constitute this intervening cause.

The immediacy of a cause being implied in its unconditionalness, is an
important clue to it; but as far as the detection of causes depends upon
sense-perception, our powers (however aided by instruments) are unequal
to the subtlety of Nature. Between the event and what seems to us the
immediate antecedent many things (molecular or etherial changes) may
happen in Chemistry or Physics. The progress of science would be
impossible were not observation supplemented by hypothesis and
calculation. And where phenomena are treated upon a large scale, as in
the biological and social sciences, immediacy, as a mark of causation,
must be liberally interpreted. So far, then, as to the qualitative
character of Causation.

(7) But to complete our account of it, we must briefly consider its
quantitative character. As to the Matter contained, and as to the Energy
embodied, Cause and Effect are conceived to be _equal_. As to matter,
indeed, they may be more properly called identical; since the effect is
nothing but the cause redistributed. When oxygen combines with hydrogen
to form water, or with mercury to form red precipitate, the weight of
the compound is exactly equal to the weight of the elements combined in
it; when a shell explodes and knocks down a wall, the materials of the
shell and wall are scattered about. As to energy, we see that in the
heavenly bodies, which meet with no sensible impediment, it remains the
same from age to age: with things 'below the moon' we have to allow for
the more or less rapid conversion of the visible motion of a mass into
other forms of energy, such as sound and heat. But the right
understanding of this point involves physi