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many into a confusion of the terms 1 force ,’ 1 energy,’ and 1 motion.’ ” Of course 
when I followed Professor Tyndall’s reasoning about heat as, not designated 
only, but actually being a mode of motion, I was obliged to follow him also 
into the hopeless confusion to which such reasoning must lead. I only 
followed him, however, that I might expose the confusion ; but by no means 
share it. It is well that Mr. Brooke holds sounder and more logical views. 
Still, after this, he should not charge me (§ 59) with “ the gratuitous substi- 
tution of the term 1 motion ’ for ‘ energy,’ ” nor say (§ 46) that I “ having 
first identified heat and motion as synonymous terms, &c.,” as though the 
identification were mine, when it is Tyndall’s. 
My views of causation are somewhat severely spoken of (§ 58), because I 
say the touch of my finger caused a book to fall to the ground. As I was not 
concerned at the moment with the theory of causation, I used the word in 
its popular sense ; occasioned would have united my purpose equally well in 
both illustrations, as the argument is not in the least affected by either word. 
I fear, however, Mr. Brooke is even as illogical as I am myself in this case, 
for while defining the causation, he says “the cause of the fall is the 
attraction of gravitation.” This is not correct, inasmuch as the cause was 
my wish to overturn the book, the attraction of gravitation being only, 
like the unstable equilibrium, a necessary condition. If there be shown 
any burlesque of physical energy in my paper, as is implied in the 
remarks in § 37, I will gladly withdraw it. So far as I am aware, any 
criticisms to which that term could be applied, are in the fancies of those 
who, while accurate observers, are but indifferent theorists ; of those who, 
to use Mr. Brooke’s own words, would misapply the conservation of energy 
“ in a fruitless endeavour to supersede the necessity of an omniscient 
Creator.” 
JAS. M‘CANN. 
Rev. John MooreA — I thank you, Mr. Chairman, for the permission you 
have granted me to take part in this discussion, and, in availing myself of 
the privilege, I wish it to be distinctly understood that it is not as a physicist 
but as a metaphysician, that I approach this question. For me, the doctrine 
of the conservation of energy had no special interest until, some six years 
ago, I read an article, by Professor Tyndall, in the Fortnightly Review , 
wherein he employs this theory to prove the futility and folly of prayer. 
This led me to make a most careful examination, and I found that the theory 
of conservation required of those who would accept it assumptions directly 
opposed to some of the best-established truths of philosophy. One of its 
main pillars is a doctrine of causation, associated with the names of Hume, 
Brown, and Mill, which I am convinced is false. We are asked to believe that 
the relation of cause and effect is nothing more than a time-relation among 
events, and, consequently, that the very important term “ Power ” does not 
symbolize anything in the nature of the cause fitting it to produce the 
effect, but denotes mere antecedence. Hence, to repeat the often used but 
still powerful illustration of Reid, it is quite correct to say that day is the 
cause of night, and night the cause of day. But, in reply, I ask what do men 
mean when they speak of the cause of a specified change ? Are they 
* Author of the article in the Quarterly Review ' called “ Heresies of 
Science,” referred to by Mr. Brooke. I regret to have to record Mr. Moore’s 
decease, which occurred before his remarks were in print. — Ed. 
