630 LOGIC OF THE MORAL SCIENCES. 



ground foi* predicting (and consequently for practically dealing with) what 

 has not yet happened, is the degree in which it would have enabled us to 

 predict what has actually occurred. Before our theory of the influence of 

 a particular cause, in a given state of circumstances, can be entirely trust- 

 ed, we must be able to explain and account for the existing state of all 

 that portion of the social phenomena Avhich that cause has a tendency to 

 influence. If, for instance, we would apply our speculations in political 

 economy to the prediction or guidance of the phenomena of any country, 

 we must be able to explain all the mercantile or industrial facts of a gen- 

 eral character, appertaining to the pi'esent state of that country ; to point 

 out causes sufticient to account for all of them, and prove, or show good 

 ground for supposing, that these causes have really existed. If we can 

 not do this, it is a proof either that the facts which ought to be taken into 

 account are not yet completely known to us, or that although we know the 

 facts, we are not masters of a sufficiently perfect theory to enable us to 

 assign their consequences. In either case we are not, in the present state 

 of our knowledge, fully competent to draw conclusions, speculative or 

 practical, for that country. In like manner, if we would attempt to judge 

 of the effect which any political institution Avould have, supposing that it 

 could be introduced into any given country, we must be able to show that 

 the existing state of the practical government of that country, and of 

 whatever else depends thereon, together with the particular character and 

 tendencies of the people, and their state in respect to the various elements 

 of social well-being, are such as the institutions they have lived under, in 

 conjunction with the other circumstances of their nature or of their posi- 

 tion, were calculated to produce. 



To prove, in short, that our science, and our knowledge of the particu- 

 lar case, render us competent to predict the future, we must show that 

 they would have enabled us to predict the present and the past. If there 

 be any thing which we could not have predicted, this constitutes a resid- 

 ual phenomenon, requiring further study for the purpose of explanation; 

 and we must either search among the circumstances of the particular case 

 until we find one which, on the principles of our existing theory, accounts 

 for the unexplained phenomenon, or we must turn back, and seek the ex- 

 planation by an extension and improvement of the theory itself. 



CHAPTER X. 



OF THE INVERSE DEDUCTIVE, OK HISTORICAL, METHOD. 



§ 1. There are two kinds of sociological inquiry. In the first kind, the 

 question proposed is, what effect will follow from a given cause, a certain 

 general condition of social circumstances being presupposed. As, for ex- 

 ample, what would be the effect of imposing or of repealing corn laws, of 

 abolishing monarchy or introducing universal suffrage, in the present con- 

 dition of society and civilization in any European country, or under any 

 other given supposition with regard to the circumstances of society in gen- 

 eral, without reference to the changes which might take place, or which 

 may already be in progress, in those circumstances. But there is also a 

 second inquiry, namely, what are the laws which determine those general 

 circumstances themselves. In this last the question is, not Avhat Avill be 

 the effect of a given cause in a certain state of society, but what are the 



