g
up no scientific evidence in support of such an hypothesis. But on the
other hand it is equally true that in the very nature of things no
such evidence could be expected to be forthcoming: even were there such
evidence in abundance, it could not be accessible to us. The existence
of a single soul, or congeries of psychical phenomena, unaccompanied
by a material body, would be evidence sufficient to demonstrate the
hypothesis. But in the nature of things, even were there a million such
souls round about us, we could not become aware of the existence of
one of them, for we have no organ or faculty for the perception of soul
apart from the material structure and activities in which it has been
manifested throughout the whole course of our experience. Even our own
self-consciousness involves the consciousness of ourselves as partly
material bodies. These considerations show that our hypothesis is very
different from the ordinary hypotheses with which science deals. The
entire absence of testimony does not raise a negative presumption except
in cases where testimony is accessible. In the hypotheses with which
scientific men are occupied, testimony is always accessible; and if we
do not find any, the presumption is raised that there is none. When Dr.
Bastian tells us that he has found living organisms to be generated in
sealed flasks from which all living germs had been excluded, we demand
the evidence for his assertion. The testimony of facts is in this case
hard to elicit, and only skilful reasoners can properly estimate its
worth. But still it is all accessible. With more or less labour it can
be got at; and if we find that Dr. Bastian has produced no evidence save
such as may equally well receive a different interpretation from that
which he has given it, we rightly feel that a strong presumption
has been raised against his hypothesis. It is a case in which we are
entitled to expect to find the favouring facts if there are any, and
so long as we do not find such, we are justified in doubting their
existence. So when our authors propound the hypothesis of an unseen
universe consisting of phenomena which occur in the interstellar ether,
or even in some primordial fluid with which the ether has physical
relations, we are entitled to demand their proofs. It is not enough to
tell us that we cannot disprove such a theory. The burden of proof lies
with them. The interstellar ether is something concerning the physical
properties