Chapter VIII.
Of The Geometrical, Or Abstract, Method.
§ 1. The misconception discussed in the preceding chapter is, as we said,
chiefly committed by persons not much accustomed to scientific
investigation: practitioners in politics, who rather employ the
commonplaces of philosophy to justify their practice than seek to guide
their practice by philosophic principles; or imperfectly educated persons,
who, in ignorance of the careful selection and elaborate comparison of
instances required for the formation of a sound theory, attempt to found
one upon a few coincidences which they have casually noticed.
The erroneous method of which we are now to treat is, on the contrary, peculiar to thinking and studious minds. It never could have suggested itself but to persons of some familiarity with the nature of scientific research; who, being aware of the impossibility of establishing, by casual observation or direct experimentation, a true theory of sequences so complex as are those of the social phenomena, have recourse to the simpler laws which are immediately operative in those phenomena, and which are no other than the laws of the nature of the human beings therein concerned, These thinkers perceive (what the partisans of the chemical or experimental theory do not) that the science of society must necessarily be deductive. But, from an insufficient consideration of the specific nature of the subject-matter--and often because (their own scientific education having stopped short in too early a stage) geometry stands in their minds as the type of all deductive science--it is to geometry, rather than to astronomy and natural philosophy, that they unconsciously assimilate the deductive science of society.
Among the differences between geometry (a science of co-existent facts, altogether independent of the laws of the succession of phenomena), and those physical Sciences of Causation which have been rendered deductive, the following is one of the most conspicuous: That geometry affords no room for what so constantly occurs in mechanics and its applications, the case of conflicting forces; of causes which counteract or modify one another. In mechanics we continually find two or more moving forces producing, not motion, but rest; or motion in a different direction from that which would have been produced by either of the generating forces. It is true that the effect of the joint forces is the same when they act simultaneously, as if they had acted one after another, or by turns; and it is in this that the difference between mechanical and chemical laws consists. But still the effects, whether produced by successive or by simultaneous action, do, wholly or in part, cancel one another: what the one force does, the other, partly, or altogether undoes. There is no similar state of things in geometry. The result which follows from one geometrical principle has nothing that conflicts with the result which follows from another. What is proved true from one geometrical theorem, what would be true if no other geometrical principles existed, can not be altered and made no longer true by reason of some other geometrical principle. What is once proved true is true in all cases, whatever supposition may be made in regard to any other matter.
