rguing from certain 'Rights of Man,' or
'Interests of Classes,' or 'Laws of Supply and Demand,' that this or
that event will happen, or ought to happen, without troubling themselves
to observe whether it does happen or ever has happened. This method of
Deduction without any empirical verification, is called by Mill the
Geometrical; and, plainly, it can be trustworthy only where there is no
actual conflict of forces to be considered. In pure mathematical
reasoning about space, time, and number, provided the premises and the
reasoning be correct, verification by a comparison with the facts may be
needless, because there is no possibility of counteraction. But when we
deal with actual causes, no computation of their effects can be relied
upon without comparing our conclusions with the facts: not even in
Astronomy and Physics, least of all in Politics.

Burke, then, has well said that "without the guide and light of sound,
well-understood principles all our reasoning in politics, as in
everything else, would be only a confused jumble of particular facts and
details without the means of drawing any sort of theoretical or
practical conclusion"; but that, on the other hand, the statesman, who
does not take account of circumstances, infinite and infinitely
combined, "is not erroneous, but stark mad--he is metaphysically mad"
(_On the Petition of the Unitarians_). There is, or ought to be, no
logical difference between the evidence required by a statesman and that
appealed to by a philosopher; and since, as we have seen, the
combination of principles with circumstances cannot, in solving problems
of social science, be made with the demonstrative precision that belongs
to astronomical and physical investigations, there remains the
Historical Method as above described.

Examples of the empirical laws from which this method begins abound in
histories, newspapers, and political discussions, and are of all shades
of truth or half-truth: as that 'History consists in the biographies of
great men'; in other words, that the movements of society are due to
exceptional personal powers, not to general causes; That at certain
epochs great men occur in groups; That every Fine Art passes through
periods of development, culmination and decline; That Democracies tend
to change into Despotisms; That the possession of power, whether by
classes or despots, corrupts the possessor: That 'the governments most
distinguished for sustained vigour and ab