touching the main branches of thought upon the matter[50].

_The remarkable nature of the facts._ These are remarkable, since they
are common to all human experience. Everything that _happens_ has a
cause. The same happening has always the same cause--or the same
consequent the same antecedent. It is only familiarity with this great
fact that prevents universal wonder at it, for, notwithstanding all the
theories upon it, no one has ever really shown why it is so. That the
same causes always produce the same effects is a proposition which
expresses a fundamental fact of our knowledge, but the knowledge of this
fact is purely empirical; we can show no reason why it should be a fact.
Doubtless, if it were not a fact, there could be no so-called 'Order of
Nature,' and consequently no science, no philosophy, or perhaps (if the
irregularity were sufficiently frequent) no possibility of human
experience. But although this is easy enough to show, it in no wise
tends to show why the same causes should always produce the same
effects.

So manifest is it that our knowledge of the fact in question is only
empirical, that some of our ablest thinkers, such as Hume and Mill, have
failed to perceive even so much as the intellectual necessity of looking
beyond our empirical knowledge of the fact to gain any explanation of
the fact itself. Therefore they give to the world the wholly vacuous, or
merely tautological theory of causation--viz. that of constancy of
sequence within human observation[51].


If it be said of my argument touching causality, that it is naturalizing
or materializing the super-natural or spiritual (as most orthodox
persons will feel), my reply is that deeper thought will show it to be