an effect occurs there can be no cause. But this
is a blunder; for whilst the word 'cause' implies 'effect,' it also
implies the relative futurity of the effect; and effect implies the
relative priority of the cause. The connotation of the words, therefore,
agrees well enough with Mill's doctrine. In fact, the danger is that any
pair of contrasted words may suggest too strongly that the phenomena
denoted are separate in Nature; whereas every natural process is
continuous. If water, dripping from the roof wears away a stone, it fell
on the roof as rain; the rain came from a condensing cloud; the cloud
was driven by the wind from the sea, whence it exhaled; and so on. There
is no known beginning to this, and no break in it. We may take any one
of these changes, call it an effect, and ask for its cause; or call it a
cause, and ask for its effect. There is not in Nature one set of things
called causes and another called effects; but every change is both cause
(or a condition) of the future and effect of the past; and whether we
consider an event as the one or the other, depends upon the direction of
our curiosity or interest.

Still, taking the event as effect, its cause is the antecedent process;
or, taking it as a cause, its effect is the consequent process. This
follows from the conception of causation as essentially motion; for that
_motion takes time_ is (from the way our perceptive powers grow) an
ultimate intuition. But, for the same reason, there is no interval of
time between cause and effect; since all the time is filled up with
motion.

Nor must it be supposed that the whole cause is antecedent to the
effect as a whole: for we often take the phenomenon on such a scale that
minutes, days, years, ages, may elapse before we consider the cause as
exhausted (e.g., an earthquake, a battle, an expansion of credit,
natural selection operating on a given variety); and all that time the
effect has been accumulating. But we may further consider such a cause
as made up of moments or minute factors, and the effect as made up of
corresponding moments; and then the cause, taken in its moments, is
antecedent throughout to the effect, taken in its corresponding moments.

(4) The Cause is the _invariable_ antecedent of the effect; that is to
say, whenever a given cause occurs it always has the same effect: in
this, in fact, consists the Uniformity of Causation. Accordingly, not
every antecedent of an event is its Cause: to assum