rds, matter and spirit are but names for the
imaginary substrata of groups of natural phenomena.

And what is the dire necessity and "iron" law under which men groan?
Truly, most gratuitously invented bugbears. I suppose if there be an
"iron" law, it is that of gravitation; and if there be a physical
necessity, it is that a stone, unsupported, must fall to the ground. But
what is all we really know, and can know, about the latter phenomenon?
Simply, that, in all human experience, stones have fallen to the ground
under these conditions; that we have not the smallest reason for
believing that any stone so circumstanced will not fall to the ground;
and that we have, on the contrary, every reason to believe that it will
so fall. It is very convenient to indicate that all the conditions of
belief have been fulfilled in this case, by calling the statement that
unsupported stones will fall to the ground, "a law of Nature." But when,
as commonly happens, we change _will_ into _must_, we introduce an idea
of necessity which most assuredly does not lie in the observed facts,
and has no warranty that I can discover elsewhere. For my part, I
utterly repudiate and anathematise the intruder. Fact I know; and Law I
know; but what is this Necessity save an empty shadow of my own mind's
throwing?

But, if it is certain that we can have no knowledge of the nature of
either matter or spirit, and that the notion of necessity is something
illegitimately thrust into the perfectly legitimate conception of law,
the materialistic position that there is nothing in the world but
matter, force, and necessity, is as utterly devoid of justification as
the most baseless of theological dogmas. The fundamental doctrines of
materialism, like those of spiritualism, and most other "isms," lie
outside "the limits of philosophical inquiry," and David Hume's great
service to humanity is his irrefragable demonstration of what these
limits are. Hume called himself a sceptic, and therefore others cannot
be blamed if they apply the same title to him; but that does not alter
the fact that the name, with its existing implications, does him gross
injustice.

If a man asks me what the politics of the inhabitants of the moon are,
and I reply that I do not know; that neither I, nor any one else, has
any means of knowing; and that, under these circumstances, I decline to
trouble myself about the subject at all; I do not think he has any right
to call me a sceptic. O