338 INDUCTION. 



them ; but the very circumstance that complicated processes of induc- 

 tion are sometimes necessary, shows that cases exist in which this 

 regular order of succession is not apparent to our first and simplest 

 apprehension. If, then, the processes which bring these cases within 

 the same category with the rest, require that we should assume the 

 universality of the very law which they do not at first sight appear to 

 exemplify, is not this a real petitio principii ? Can we prove a propo- 

 sition, by an argument which takes it for granted "? And if not so 

 proved, on what evidence does it rest 1 



For this difliculty, which I have purposely stated in the strongest 

 terms it would admit of, the school of metaphysicians who have long 

 predominated in this country find a ready salvo. They affirm, that the 

 universality of causation is a truth which we cannot help believing ; 

 that the belief in it is an instinct, one of the laws of our believing 

 faculty. As the proof of this, they say, and they have nothing else to 

 say, that everybody docs believe it ; and they number it among the 

 propositions, rather nuinerous in their catalogue, which may be logi- 

 cally argued against, and perhaps cannot be logically proved, but which 

 are of higher authority than logic, and which even he who denies in 

 speculation, shows by his habitual practice that his arguments make 

 no impression upon himself 



I have no intention of entering into the merits of this question, as a 

 problem of transcendental metaphysics. But I must renew my protest 

 against adducing as evidence of the truth of a fact in external nature, 

 any necessity which the human mind may be conceived to be under of 

 believing it. It is the business of the human intellect to adapt itself to 

 the realities of things, and not to measure those realities by its own capa- 

 cities of comprehension. The same quality which fits mankind for the 

 offices and purposes of their own little life, the tendency of their belief 

 to follow their experience, incapacitates them for judging of what lies 

 beyond. Not only what man can know, but what he can conceive, 

 depends upon what he has experienced. Whatever forms a part of all 

 his experience, forms a part also of all his conceptions, and appears to 

 . him universal and necessary, though z-eally, for aught he knows, having 

 no existence beyond certain nan-ow limits. The habit, however, of 

 philosophical analysis, of Avhich it is the surest effect to enable the 

 mind to command, instead of being commanded by, the laws of the 

 merely passive part of its own nature, and which, by showing to us 

 that things are not necessarily connected in fact because their ideas 

 are connected in our minds, is able to loosen innumerable associations 

 which reign despotically over the undisciplined mind ; this habit is not 

 without power even over those associations which the philosophical 

 school of which I have been speaking, regard as connate and instinc- 

 tive. I am convinced that any one accustomed to abstraction and 

 analysis, who will fairly exert his faculties for the purpose, will, when 

 his imagination has once learnt to entertain the notion, find no difficulty 

 in conceiving that in some one for instance of the many firmaments 

 into which sidereal astronomy now divides the universe, events may 

 succeed one another at random, without any fixed law; nor can any- 

 thing in our experience, or in our mental nature, constitute a sufficient, 

 or indeed any, reason for believing that this is nowhere the case. The 

 grounds, therefore, which waiTant us in rejecting such a supposition 

 with respect to any of the phenomena of which we have experience, 



