APPROXIMATE GENERALIZATIONS. 353 



do; aucl must make up as far as possible for the incomplete conclusive- 

 ness of any one indication, by obtaining others to corroborate it. The 

 principles of induction applicable to ap[)roxiniate geiieiahzation are 

 therefore a not loss important subject of iiujuiry, than the rules for the , 

 investigation of universal truths; and might reasonably be ex[)ected 

 to detain us almost as long, were it not that these principles are mere 

 GOrollanes from those which have been already treated of. 



§ 3. There are two sorts of cases in which we arc forced to guide 

 ourselves by generalizations of the imperfect foi'm. Most A are B. 

 The first is, when we have no others ; when we have not been able to 

 carry our investigation of the laws of the phenomena, any further; 

 as in the following propositions : Most dark-eyed persons have dark 

 hail- ; Most springs contain mineral substances ; Most stratified fijrma- 

 tions contain fossils. The importance of this class of generalizations is 

 not very gieat ; for, though it frequently liappens that we see no I'ea- 

 son why that which is true of most individuals of a class is not true of 

 the remainder, nor are able to bring the former under any general 

 description which can distinguish them from the latter, yet if we are 

 willing to be satisfied, with propositions of a less degi'ee of generality, 

 and to break down the class A into sub-classes, we may generally 

 obtain a collection of propositions exactly true. We do not know why 

 most wood is lighter than water, nor can we point out any general 

 property which discriminates wood that is lighter than water from that 

 which is heavier. But we know exactly what species are the one and 

 what the other. And if we meet with a specimen not confoi'mable to 

 any known species (the only case in which our previous knowledge 

 ciffbrds no other guidance than the approximate generalization), we 

 can generally make a specific experiment, which is always a safer 

 resource. 



It oftener happens, however, that the proposition. Most A are B, is 

 not the ultimatum of our scientific pi'ogress, though the knowledge we 

 possess beyond it cannot conveniently be brought to bear upon the 

 particular instance. In such a case, we know well enough what cir- 

 cumstances really distinguish the portion of A which have the attribute 

 B from the portion which have it not, but have no means, or no time, 

 to examine whether those characteristic circumstances exist or not in 

 the individual case. This is generally the situation we are in when 

 the in(|uiry is of the kind called moral, that is, of the kind which have 

 in view to predict human actions. To enable us to affirm anything 

 universally concerning the actions of classes of men, the classification 

 must be grounded upon the circumstances of their mental cultm-e and 

 habits, which in an individual case are seldom exactly known; and 

 classes grounded on these distinctions would never precisely accbi-d 

 with those intcj which mankind are necessarily divided for social 

 purposes. All propositions which can be framed respecting the actions 

 of men as ordinarily classified, or as classified according to any kind of 

 outward indications, are merely approximate. We can only say, Most 

 men of a particular age, profession, country, or rank in society, have 

 such and such qualities, or. Most persons when placed in certain cir- 

 cumstances act in such and such a way. Not that we do not in general 

 know well enough upon what causes the qualities depend, or what sort 

 of persons they are who act in that particular way ; but we have sel- 



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