Political and social phenomena have been thought too complex for scientific treatment. Practitioners hitherto have been the only students; and so, as in medicine, before the rise of Physiology and Natural History, _experimenta fructifera_, and not _lucifera_, have been sought. The scheme of such a science has even been thought quackery, through the vain attempts of some theorists to frame universal precepts, as though their failure (arising from the variety of human circumstances) proved that the phenomena do not conform to universal laws. Social phenomena, however, being phenomena of human nature in masses, must, as human nature is itself subject to fixed laws, obey fixed laws resulting from the fixed laws of human nature. The number and changefulness of the data (unlike those of Astronomy) will prevent our ever predicting the far future of society. But, when general laws have been ascertained, an application of them to the individual circumstances of a given age and country will show us the causes and tendencies of, and the means of modifying, its actual condition. A consideration of two methods, erroneously used for this science, viz. the Experimental or Chemical, and the Abstract or Geometrical, will introduce us to the true one. CHAPTER VII. THE CHEMICAL, OR EXPERIMENTAL, METHOD IN THE SOCIAL SCIENCE. The followers of this method do not recognise the laws of social phenomena as merely a composition of the laws of individual human nature. They demand specific experience in all cases; and they attempt to make effects, which depend on the greatest possible complication of causes, the subject of induction by observation and experiment. The attempt must fail; for, we can neither get by experiment appropriate _artificial_ instances, nor, by observation, _spontaneous_ instances (from history), with the circumstances enough varied for a true induction. Neither the _direct_ nor the _indirect_ Method of Difference can be applied, for we cannot find either two single instances differing in nothing but the presence or absence of a given circumstance (the _direct_), or two classes respectively agreeing in nothing but the presence of a circumstance on one side and its absence on the other (the _indirect_). Then, again, the Method of Agreement is of small value, because social phenomena admit the widest plurality of causes; and so also is that of Concomitant Variations, on account of the mutual action of the coexisting elements of society being such that what affects one affects all. The Method of Residues is better suited to social enquiries than the other three. But _it_ is not a method of pure observation and experiment. It presupposes that we know, by previous deduction from principles of human nature, the causes of part of the effect. But if thus part of the truths are, why may not all be, ascertained by Deduction, and the experimental argument be confined to the verifying of the deductions? CHAPTER VIII.