86 THE SCIENCE OF LOGIC 



On the other hand, were we to understand by the &quot; cause &quot; of 

 a given kind of event not any and every factor (or group of fac 

 tors) capable of producing it, but that precise factor (or group), 

 and that only, which (being present in all modes of producing it) 

 is itself capable, and alone capable, of producing the event, then 

 this kind of event can be produced by that one &quot; cause,&quot; and by 

 it alone. In other words, no event can have a &quot;plurality of 

 causes &quot; in this stricter sense of the term &quot; cause V The doctrine 

 that the same effect can have a &quot; plurality of causes &quot; holds good 

 &quot;as long as the cause* is understood in the popular way. The 

 plurality disappears before any exact scientific investigation&quot;? 

 The subtraction of any factor from the &quot; total cause &quot; in this 

 strict scientific sense, or the addition of any new factor to it, must 

 necessarily modify the effect : no other factors or combinations 

 of factors .could produce this sort of effect exactly and identically. 

 This is but a simple application of the principle of identity. E 

 is an effect whose total cause (or, the totality of whose sufficient 

 and indispensable antecedents) is a + b + c. But, if it is so, it 

 cannot at the same time, being and remaining identical with it 

 self, be the result of a + b + c + d, or of a + b + d, or of a + 6, 

 or of m + b + y, or of any other conceivable combination. 3 



222. SCIENCE AND THE DISCOVERY OF &quot;CAUSES&quot; AND 

 &quot; LAWS &quot;. In popular thought, therefore, the notion of &quot; physical 

 cause &quot; usually includes elements not indispensable to the pro 

 duction of the effect, though the notion of the &quot; effect &quot; does not 

 include any element which is not necessitated by some element 

 or other of the cause. 4 The reason for this peculiar difference 



1 The mediaeval Scholastics discussed &quot; plurality of causes &quot; in connexion 

 chiefly with the individual effect, and the principle or ground of its individuation ; 

 proposing the problem in terms like these : &quot; Would Alexander the Great have been 

 the same individual had he been born of other parents than Philip and Olympia ? &quot; 

 Their answer was usually in the negative. C/. ZIGLIARA, Ontologia (46), vii. 



2 MELLONE, op. cit., p. 277. 3 Cf. JOSEPH, op. cit., pp. 377-8. 



4 We say &quot;usually,&quot; for there are evidences that the popular mind is quite 

 familiar with some applications of the scientific conception itself: for instance, with 

 the procedure at coroners inquests, and with the convictions of criminals on circum 

 stantial evidence. &quot; The popular idea of the non-reciprocal character of the axiom 

 of causation,&quot; writes Professor Welton, &quot; is due to the fact that the cause is much 

 more frequently analysed than the effect using those words in the popular 

 sense of temporal antecedent and consequent phenomena. Thus, when Mill says 

 in support of his doctrine of the Plurality of Causes, Many causes may produce 

 death (op. cit., Bk. III., ch. x., i), he is obviously speaking very loosely. Death 

 is not the whole effect. Moreover, death can never be death in general, but only 

 some one particular kind of death, and the death caused by a bullet through the 

 heart is not the same kind of death as that due to drowning, and both again differ 



