252 THE POPULAR SCIENCE MONTHLY. 



effect ; and these effects being invariably connected will, by ignorant 

 people, be regarded as cause and effect, which they will not be. In 

 fact, the reference of one phenomenon to another as its cause, in con- 

 sequence of invariable sequence, may have the same essential error in- 

 volved in it as had the classical example of Tenterden Steeple and the 

 Goodwin Sands. 



"What is necessary in order that one thing shall be regarded as the 

 effect of another, which may be called the cause, is not only that there 

 shall be an invariable sequence, but also that it shall be i^ossible to as- 

 sert that the one could not take place without the other, or something 

 equivalent. This invisible, impalpable chain between the one thing 

 and the other must be postulated by the human mind : it constitutes 

 the idea of cause ; every child knows perfectly well what it is, and 

 the profoundest philosopher does not go far, if at all, beyond the 

 knowledge of the child. 



Let me support what I have been saying by a quotation from 

 Whewell's '* Philosophy of the Inductive Sciences " : 



We see in the world around us a constant succession of causes and effects 

 connected with each otlier. The laws of this connection we learn in a great 

 measure from experience, by observation of the occurrences which present them- 

 selves to our notice, succeeding one another. But in doing this, and in attending 

 to this succession of appearances, of which we are aware by means of our senses, 

 we supply from our mind the idea of cause. This idea, as we have already 

 shown with respect to other ideas, is not derived from experience, but has its 

 origin in the mind itself ; is introduced into our experience by the active not by 

 the passive part of our nature.* 



And again Dr. Whewell writes : 



That this idea of cause is not derived from experience, we prove (as in former 

 cases) by tliis consideration : that we can make assertions, involving this idea, 

 which are rigorously necessary and universal ; whereas knowledge derived from 

 experience can only be true as far as experience goes, and can never contain in 

 itself any evidence whatever of its necessity. "We assert that " every event must 

 have a cause " ; and this proposition we know to be true, not only probably 

 and generally, and as far as we can see ; but we can not suppose it to be false 

 in any single instance. We are as certain of it as of the truths of arithmetic or 

 geometry.t 



Here is a true postulate ; and if to the postulate that every event 

 must have a cause we add these postulates, (1) that causes in Nature 

 are always of the same kind and always act in the same way, and (2) 

 that no new causes come into existence, we should go a long way 

 toward making the uniformity of Nature, if not axiomatic, at all events 

 capable of tolerably simple and satisfactory demonstration. 



But these latter postulates will perhaps scarcely be universally 

 granted. I understand those disputants, who in the Metaphysical 

 Society's discussion laid so much stress upon the duty of examining 

 * Vol. i, p. 158, f Page 159. 



