but it may serve as a map and a mnemonic. The stages in the evolution of ideas have had almost
the quality of the Hegelian dialectic: doctrines have developed, by steps that each seem natural,
into their opposites. But the developments have not been due solely to the inherent movement of
ideas; they have been governed, throughout, by external circumstances and the reflection of these
circumstances in human emotions. That this is the case may be made evident by one outstanding
fact: that the ideas of liberalism have undergone no part of this development in America, where
they remain to this day as in Locke.
Leaving politics on one side, let us examine the differences between the two schools of
philosophy, which may be broadly distinguished as the Continental and the British respectively.
There is first of all a difference of method. British philosophy is more detailed and piecemeal than
that of the Continent; when it allows itself some general principle, it sets to work to prove it
inductively by examining its various applications. Thus Hume, after announcing that there is no
idea without an antecedent impression, immediately proceeds to consider the following objection:
suppose you are seeing two shades of colour which are similar but not identical, and suppose you
have never seen a shade of colour intermediate between the two, can you nevertheless imagine
such a shade? He does not decide the question, and considers that a decision adverse to his general
principle would not be fatal to him, because his principle is not logical but empirical. When--to
take a contrast--Leibniz wants to establish his monadology, he argues, roughly, as follows:
Whatever is complex must be composed of simple parts; what is simple cannot be extended;
therefore everything is composed of parts having no extension. But what is not extended is not
matter. Therefore the ultimate constituents of things are not material, and, if not material, then
mental. Consequently a table is really a colony of souls.
The difference of method, here, may be characterized as follows: In Locke or Hume, a
comparatively modest conclusion is drawn from a broad survey of many facts, whereas in Leibniz
a vast edifice of deduction is pyramided upon a pin-point of logical principle. In Leibniz, if the
principle is completely true and the deductions are entirely valid, all is well; but the structure is
unstable, and the slightest flaw anywhere brings it down in ruins. In Locke or Hume, on the