ENDS AND MEANS
not phenomena but 'epiphenomena/ facts of consciousness)
they should feel themselves justified in making inductions
about all phenomena past, present and future, constitutes
in itself a sufficient denial of the validity of *nothing-but*
judgments concerning the nature of the mind. All science
is based upon an act of faith—faith in the validity of the
mind's logical processes, faith in the ultimate explicability
of the world, faith that the laws of thought are laws of
things. In practice, I repeat, if not always in theory, $uch
conceptions are fundamental to all scientific activity. For
the rest, scientists are opportunists. They will pass from
a common-sense view of the world to advanced idealist
' theories, making use of one or the other according to the
field of study in which they are at work. Unfortunately,
few scientists in these days of specialization are ever called
upon to work in more than one small field of study. Hence
there is a tendency on the part of individual specialists to
accept as true particular theories which are in fact only
temporarily convenient. It is highly unfortunate that so
few scientists are ever taught anything about the meta-
physical foundations of science.
Recent research in medicine, in experimental psychology
and in what is still called parapsychology has thrown some
light on the nature of mind and its position in the world.
During the last forty years the conviction has steadily grown
among medical men that very many cases of disease, organic
as well as functional, are directly caused by mental states. (
The body becomes ill because the mind controlling it either
secretly wants to make it ill, or else because it is in such a
state of agitation that it cannot prevent the body from
sickening. Whatever its physical nature, resistance to
disease is unquestionably correlated with the psychological
condition of the patient.1 That even so grossly c physical'
1 For the physical basis of resistance, 'see The Nature of Disease,
by J. E. R. McDonagh, F.R.C.S.
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