THE EVIDENCE OF THE LAW OF UNIVERSAL CAUSATION.
The validity of all the four inductive methods depends on our assuming
that there is a cause for every event. The belief in this, i.e. in the
law of universal causation, some affirm, is an instinct which needs no
warrant other than all men's disposition to believe it; and they argue
that to demand evidence of it is to appeal to the intellect from the
intellect. But, though there is no appeal from the faculties all
together, there may be from one to another: and, as belief is not proof
(for it may be generated by association of ideas as well as by
evidence), a case of belief does require to be proved by an appeal to
something else, viz. to the faculties of sense and consciousness.
The law of universal causation is, in fact, a generalisation from many
partial uniformities of sequence. Consequently, like these, which cannot
have been arrived at by any strict inductive method (for all such
methods presuppose the law of causation itself), it must itself be based
on inductions _per simplicem enumerationem_, that is, generalisations of
observed facts, from the mere absence of any known instances to the
contrary. This unscientific process is, it is true, usually delusive;
but only because, and in proportion as, the subject-matter of the
observation is limited in extent. Its results, whenever the number of
coincidences is too large for chance to explain, are empirical laws.
These are ordinarily true only within certain limits of time, place, and
circumstance, since, beyond these, there may be different collocations
or counteracting agencies. But the subject-matter of the law of
universal causation is so diffused that there is no time, place, or set
of circumstances, at least within the portion of the universe within our
observation, and adjacent cases, but must prove the law to be either
true or false. It has, in fact, never been found to be false, but in
ever increasing multitudes of cases to be true; and phenomena, even
when, from their rarity or inaccessibility, or the number of modifying
causes, they are not reducible _universally_ to any law, yet _in some
instances_ do conform to this. Thus, it may be regarded as coextensive
with all human experience, at which point the distinction between
empirical laws and laws of nature vanishes. Formerly, indeed, it was
only a very high probability; but, with our modern experience, it is,
practically, absolutely certain, and it confirms the particular laws of
causation, whence itself was drawn, when there seem to be exceptions to
them. All narrower inductions got by simple enumeration are unsafe,
till, by the application to them of the four methods, the supposition of
their falsity is shown to contradict _this_ law, though it was itself
arrived at by simple enumeration.