CONCEPTS OF &quot; REASON &quot; AND &quot; CA USE &quot; 77 



by reason of any extrinsic conditions, but unconditionally and by 

 reason of the nature of the phenomena themselves which constitute 

 the sequence, Mill evidently intended to convey that an antecedent, 

 in order to be a &quot;cause,&quot; must have a &quot;necessary&quot; connexion 

 with its consequent. This conception of the &quot;cause&quot; of a 

 phenomenon as something which, of itself, of its own nature, 

 and not by reason of any extrinsic conditions, is invariably 

 followed by that phenomenon is precisely what had suggested 

 the traditional notion of a necessary as opposed to a free cause : 

 we are prompted to regard a cause as necessarily productive of an 

 effect by observing it to be always and in all circumstances 

 followed by that effect. By making the invariability of the con 

 nexion independent of all other conditions, and thus, as the only 

 alternative, dependent on the nature of the connected phenomena 

 themselves, Mill believed that he was giving intelligible ex 

 pression to 



&quot; what writers mean when they say that the notion of cause involves the idea of 

 necessity. If there be any meaning which confessedly belongs to the term 

 necessity, it is unconditionalness. That which is necessary, that which must be, 

 means that which will be, whatever supposition we may make in regard to all 

 other things. The succession of day and night evidently is not necessary in 

 this sense. It is conditional on the occurrence of other antecedents. That 

 which will be followed by a given consequent when, and only when, some 

 third circumstance also exists, is not the cause, even though no case should 

 ever have occurred in which the phenomenon took place without it. ... Let 

 me add that the antecedent which is only conditionally invariable, is not the 

 invariable antecedent [in the full sense of absolutely invariable in the future as 

 in the past ?]. Though a fact may in experience have always been followed by 

 another fact, yet if the remainder of our experience teaches us that it might 

 not always be so followed, or if the experience itself is such as leaves room for a 

 possibility that the known cases may not correctly represent all possible cases, 

 the hitherto invariable antecedent is not accounted the cause ; but why ? 

 Because we are not sure that it is the [really, absolutely, unconditionally] in 

 variable antecedent &quot;- 1 



But the idea of &quot; necessity &quot; is not the idea of actually uni 

 form and unvaried sequence, though it is derived from our ex 

 perience of the latter ; or of invariable sequence, except we take 

 invariable to mean not only that which has not varied and does 

 not and will not vary, but that which cannot vary. And in 

 variability in this latter sense need not be at all unconditional in 

 order to be described as &quot; necessity,&quot; for the &quot; necessity &quot; itself 

 may conceivably be conditional : we can quite conceive a sequence 



i ibid., 6. 



