If our interests were single and uniform, one consistent scheme of
intellectual knowledge would suffice. We need never be in fundamental
contradiction with ourselves. Every advance in knowledge would
illustrate and confirm what we had already learned.
But we are not of this simple constitution. We are first and
essentially minds, we are next and temporarily embodied minds, and
in each of these characters we have distinct and, to a great extent,
conflicting interests. Hence we have to acquire different species of
knowledge and admit different standards of truth. The ideas that serve
the interests of the embodied man are false to the same man considered
apart from his embodiment, and contrariwise--false, in the sense of
being useless and perhaps misleading.
Hence the existence of Common-sense for the embodied interests,
and Philosophy for the purely mental interests. Science is common
knowledge carried to its utmost perfection, but not partaking in the
least of the philosophical character.
_Realism_ is the notion of perception that is acquired with our common
knowledge. It is seldom explicitly defined or defended, for in order
to this a comparison with philosophic theories would have to be made,
and the defects of realism would be apparent. The realistic view is so
named by philosophers to distinguish it from their own views.
For corporeal purposes it is useful to believe, and it is therefore
relatively true, that there is a real space which would exist although
all objects were removed from it. Objects are real solid things
stored in space like casks in a cellar. They have fixed dimensions
notwithstanding that they appear to contract and dilate as we leave or
approach them. It is quite 'natural' they should appear smaller at a
distance. Distant perception is conceivable, therefore it is possible,
and since calculations based on this assumption are verified by
experience, it must and does take place. Time also is as real as
space, and would exist by itself though space and its contents were
annihilated. It is a sort of stream.
All these propositions are true for certain necessary purposes. We
begin to form such ideas from the moment we are born, and during the
years of infancy we are doing nothing else intellectually but working
out the notions of space, time, magnitude, distance. Most of our
school education is of the same kind. By the time we reach maturity
realism has become so rooted in our intellect that--as regards the
majority of men--no sceptical considerations are strong enough
to unsettle them. For why? They enable the natural man to provide
sufficiently well for his bodily needs and other needs depending
therefrom, and he has therefore no motive for doubting his realism or
for acquiring any other sort of ideas. He is quite right to abide by
those which have answered his purposes.
It is not from without but from within that doubts arise as to
realistic truth. They arise when the mind has acquired power over and
above what is needed for bodily uses, and begins to think on its own
account. Sentiments are felt which do not depend on or refer to bodily
life, and a new intellect has to be formed to explain and protect
these sentiments. This new intellect is Philosophy. It is the science
and practical conduct of mind considered as abstracted from body.
Much of the obscurity of philosophy is traceable to the superstition
of a fixed standard of truth which must be recognised universally.
We are reluctant to accept philosophical hints and inferences
because they conflict with truths that have been physically verified.
Or--which is more common--we take up a few philosophical propositions
and tack on to them all the science we know, believing they make a
homogeneous whole, because truth must be self-consistent.
Time and labour would be spared if we could be told at the right
moment that truth is expedience[4], and that there is no need to
harmonise philosophy and science. We are each of us two men in one,
and each of these men must be allowed to think for himself. There is
no reason why they should quarrel; there is no reason why they should
even argue. The science in our mind should not be ousted to make room
for the philosophy; let them exist together and work alternately. When
the mariner is at sea he must mind his ship and study the weather;
when he is on shore he may neglect both. So when we are navigating
the body we have to think in categories proper to its safety; as
philosophers we dismiss the realistic categories and think in other
forms, but we need not then call the realism false or foolish. In its
proper place it is right and true[5].
Between realism and substantialism there is therefore no necessary
conflict or competition. They are each indispensable. It is absurd
to carry realism into philosophy, and no less absurd to carry
substantialism into common affairs, or to reproach a substantialist
because he acts and speaks occasionally like other people. It
is probable however that in a community largely composed of
substantialists the realism of common action would be less stringent
than is now found necessary.
[Footnote 3: _Will in Nature_, 'Physiology of Plants.']
[Footnote 4: This does not apply to truth in the sense of
veracity.]
[Footnote 5: Greek philosophers never understood the dual
standard of Truth, and insisted that philosophy was the best
preparation for every sort of employment. The people, though
generally unwise in political matters, had sense enough not to
entrust the care of their temporal interests to philosophers,
and so the universal utility of philosophy had few
opportunities of being tested. A Macedonian king committed the
custody of Corinth and its citadel to a philosopher, Persaeus,
who was promptly expelled by Aratus--a mere soldier. Persaeus
frequented the schools again, and on the well-worn theme that
'none but a wise man is fit to be a general' being brought up
for discussion, he said, 'It is true, and the gods know it,
that this maxim of Zeno once pleased me more than all the
rest; but I have changed my opinion since I was taught better
by the young Sicyonian.'--Plutarch's _Life of Aratus_.]