89 
But leaving this consideration and conceding for the moment 
all that Prof. Tyndall violently and unscientifically assumes, 
viz. : that the animal body is a machine — let us follow him up 
to the line where its supposed relations to the soul begin. We 
accept the case suggested by himself : “ An aerial wave, the 
energy of which would not reach a minute fraction of that 
necessary to raise the thousandth of a grain through the 
thousandth of an inch, can throw the human frame into a 
powerful mechanical spasm followed by violent respiration and 
palpitation.” We give the illustration which he quotes from 
Lange. ‘ A merchant sits quietly in his chair — he reads a letter, 
it makes him spring to his feet, he calls his carriage, gives 
orders in haste to all his clerks and servants — rushes on Chang-e, 
buys, and sells, and signs a few papers, and in a half-hour has 
saved his fortune from wreck ; he comes back, and throwing 
himself into his chair says, now I can breathe.'’ “ This com- 
plex mass of action, emotional, intellectual, and mechanical, is 
evoked by the impact upon the retina of the infinitesimal 
waves of light coming from a few pencil marks on a bit of 
paper.” “ What caused the merchant to spring out of his chair ? 
The contraction of his muscles. What made his muscles con- 
tract ? An impulse of the nerves which lifted the proper latch 
and liberated the muscular power. Whence this impulse ? 
From the centre of the nervous system. But how did it origi- 
nate there ? This is the critical question.” It is indeed the 
critical question. And how does Prof. Tyndall answer it ? We 
should first inquire, how does he ask it ? for it is important 
to notice that as with lawyers so with philosophers it often 
happens that the way in which they phrase their questions re- 
veals the answers which they expect or desire, and in some sort 
compel. Prof. Tyndall does not deny that other phenomena 
come in beside those of the ordinary nervous, digestive, and 
breathing mechanism. He admits that terror and hope, sensa- 
tion and calculation, with possible ruin, all succeed, one another 
between the impact on the retina and the lifting the latch 
which releases the reaction that proceeds from the centre of the 
nervous system. But he assumes that whatever is the nature 
look the fact, that tried by this test, physiology itself, as conceived by the 
great majority of its devotees, is as little a science as psychology. His own 
conjectures that the animal body is a machine, are as far from any mathe- 
matical formalization as the not dissimilar theory of Descartes. The psycho- 
logical theories of the school of Herbart are more solidly and consistently 
mathematical than are the headlong guesses of Prof. Tyndall’s physiology. 
Tried by Tyndall’s test, the new chemistry is also in some danger of being 
pronounced unscientific. See Du Bois Beymond . — XJcbcr die Grenzen des 
Naturerlcennens, pp. 4, 5. 
