_Symbolic Conceptions._
Observe the meaning of this distinction. Of any simple object which
can be grasped in a single act of perception, such as a knife or a
book, an egg or an orange, a circle or a triangle, you can frame a
conception which almost or quite exactly _represents_ the object.
The picture or visual image in your mind when the orange is present
to the senses is almost exactly reproduced when it is absent. The
distinction between the two lies chiefly in the relative vividness of
the former as contrasted with the relative faintness of the latter.
But as the objects of thought increase in size and in complexity of
detail, the case soon comes to be very different. You cannot frame
a truly representative conception of the town in which you live,
however familiar you may be with its streets and houses, its parks and
trees, and the looks and demeanour of the townsmen; it is impossible
to embrace so many details in a single mental picture. The mind must
range to and fro among the phenomena in order to represent the town
in a series of conceptions. But practically what you have in mind
when you speak of the town is a fragmentary conception in which some
portion of the object is represented, while you are well aware that
with sufficient pains a series of mental pictures could be formed
which would approximately correspond to the object. That is to say,
this fragmentary conception stands in your mind as a _symbol_ of
the town. To some extent the conception is representative, but to a
great degree it is symbolic. With a further increase in the size and
complexity of the objects of thought, our conceptions gradually lose
their representative character, and at length become purely symbolic.
No one can form a mental picture that answers even approximately to the
earth. Even a homogeneous ball eight thousand miles in diameter is too
vast an object to be conceived otherwise than symbolically, and much
more is this true of the ball upon which we live, with all its endless
multiformity of detail. We imagine a globe and clothe it with a few
terrestrial attributes, and in our minds this fragmentary notion does
duty as a symbol of the earth.
The case becomes still more striking when we have to deal with
conceptions of the universe, of cosmic forces such as light and heat,
or of the stupendous secular changes which modern science calls us to
contemplate. Here our conceptions cannot even pretend to represent
the objects; they are as purely symbolic as the algebraic equations
whereby the geometer expresses the shapes of curves. Yet so long as
there are means of verification at our command, we can reason as safely
with these symbolic conceptions as if they were truly representative.
The geometer can at any moment translate his equation into an actual
curve, and thereby test the results of his reasoning; and the case is
similar with the undulatory theory of light, the chemist's conception
of atomicity, and other vast stretches of thought which in recent times
have revolutionized our knowledge of Nature. The danger in the use of
symbolic conceptions is the danger of framing illegitimate symbols
that answer to nothing in heaven or earth, as has happened first and
last with so many short-lived theories in science and in metaphysics.
Forewarned of this danger, and therefore--I hope--forearmed against it,
let us see what a scientific philosophy has to say about the Power that
is manifested in and through the universe.