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of these phenomena they are caused by the impact of the un- 
dulating light upon the responsive retina/ that this imparts 
another impact to a somewhat causing terror, which in its turn 
by another stroke or impact is transformed into hope, till at 
last the latch is lifted and the muscular power is set free. This 
assumption concerning all these processes resolves them into 
mechanism and subjects them to the law of necessity. It takes 
for granted that whatever the soul may be, whether it is a set 
of friction wheels or a voltaic battery, whether brain or a 
poetical expression for an ideal x, its phenomena are caused at 
first by the impact of a material object and follow in succession 
according to mechanical necessity. The proper attitude to 
assume is of protest against every such assumption and the 
language which asserts or implies it. The true and wary 
philosopher will say just at this point, I do not accept your 
version of these intervening phenomena, they are in no sense 
evoked by the object striking upon the man, but they are per- 
formed by the man with reference to the object. It is not the 
letter which strikes its impacts upon the man, but it is the man 
who reads the letter and thereafter acts in calculation and hope 
until the latch is lifted and the muscular motion is set free. 
We know that this view is very strange to Prof. Tyndall’s 
method of philosophizing and is fatal to all his conclusions, but 
in our view it is true to the facts, and we must protest against 
this stealthy if it be an unconscious way of disguising the facts 
by the mode of asking the question, Whence the impulse and 
how did it originate, that directs or liberates motion in the 
various methods so vividly described? This is indeed the 
critical question. It is none other than whether there is any 
other agont than matter, and whether the agent, be it material 
or aught besides, acts according to mechanical laws and under 
mechanical necessity ? How does Prof. Tyndall answer this 
question ? Ho remarks first of all, “ The aim and effort of 
Science is to explain the unknown in terms of the known. 
Explanation, therefore, is conditioned by knowledge.” This 
truth he proceeds to illustrate by the story of a German 
peasant, who, when he saw a locomotive for the first time, 
having never known any other than animal power, after long 
reflection solemnly said : Es mussen Pferde darin seyn : There 
are horses inside ! The story in Prof. Tyndall’s opinion illus- 
trates a deep-lying truth. It strikes us that the deep-lying 
truth which Prof. Tyndall finds in it admits of an application 
of which he was not fully aware or he would scarcely have in- 
troduced the story. Had the peasant known no other loco- 
motivo power than that by horses, ho had reasoned wisely, 
provided the peculiarity of the effect was not fitted to awaken 
