are satisfied that, as they are not now where you left them, they have
been removed. In the third place, you look at the marks on the
window-sill, and the shoemarks outside, and you say that in all
previous experience the former kind of mark has never been produced by
anything else but the hand of a human being; and the same experience
shows that no other animal but man at present wears shoes with
hob-nails on them such as would produce the marks in the gravel. I do
not know, even if we could discover any of those "missing links" that
are talked about, that they would help us to any other conclusion! At
any rate the law which states our present experience is strong enough
for my present purpose.--You next reach the conclusion, that as these
kinds of marks have not been left by any other animals than men, or are
liable to be formed in any other way than by a man's hand and shoe, the
marks in question have been formed by a man in that way. You have,
further, a general law, founded on observation and experience, and
that, too, is, I am sorry to say, a very universal and unimpeachable
one,--that some men are thieves; and you assume at once from all these
premisses--and that is what constitutes your hypothesis--that the man
who made the marks outside and on the window-sill, opened the window,
got into the room, and stole your tea-pot and spoons. You have now
arrived at a 'Vera Causa';--you have assumed a Cause which it is plain
is competent to produce all the phenomena you have observed. You can
explain all these phenomena only by the hypothesis of a thief. But
that is a hypothetical conclusion, of the justice of which you have no
absolute proof at all; it is only rendered highly probable by a series
of inductive and deductive reasonings.

I suppose your first action, assuming that you are a man of ordinary
common sense, and that you have established this hypothesis to your own
satisfaction, will very likely be to go off for the police, and set