1878.] 
Notices of Books. 
127 
pointed out before, but which is yet of exceeding value as clearly 
and authoritatively summing up the methods by which alone 
scientific truth may be attained. These methods are too apt to 
be sneered at by mere paper philosophers, the professors of the 
so-called “ Wissenschaft in der phrase;” they are practically 
overlooked by the young, the inexperienced, and the superficial, 
who have yet to learn the great lesson of thoroughness. Hence it is 
most appropriate that they should be fully explained and enforced 
at such a time as the opening of a course of study in a new in- 
stitution for higher — and we hope for scientific — education. 
Mr. Thompson naturally addresses himself to the student of 
physics or of chemistry, but he says little, if anything, which has 
not an equal claim of the biologist or the geologist, in short, of 
all who in any department are engaged in questioning nature. 
The leCturer takes for his text, if we may use the expression, 
the “Rules of Philosophising” laid down by Newton in his 
“ Principia.” 
I. “We are to admit no more causes ot natural things than 
such as are both true and sufficient to explain their appearances.” 
II. “ To the same natural effects, therefore, we must, as far as 
possible, assign the same causes.” 
A striking example of the breach of these two rules is given by 
certain biologists in their attempts to deny intelligence to the 
lower animals. If a man acts in a certain manner to attain a 
given end, they declare he has been guided by intelligence, but if 
a fox or an ape proceeds in a manner totally analogous they then 
ascribe his conduct to quasi- intelligence, and thus assign different 
causes to the same natural effeCts. 
The author refers to a “ certain note of dissatisfaction at the 
methods of modern science, and that in quarters where it cannot 
be passed by ; a dissatisfaction amounting almost to disgust. 
This “ revolt from the experimental method ” is manifested in the 
writings of Hegel, and finds an echo in a passage quoted by the 
author from Buckle’s “ History ot Civilisation ” (vol. iii., p. 379). 
We may even doubt whether Comte can be altogether acquitted 
of having given utterance to similar views. This same tendency 
to undervalue experiment and observation and to return to the 
vicious methods pursued in the dark ages may be traced in an 
advice given in a certain quarter to naturalists that they ought by 
all means to study metaphysics. But it is not from open attacks 
upon the induClive method that we have the most to fear. It is 
manifestly not merely the right but the duty of science to subjeCt 
every phenomenon to the test of experimental study. No matter 
how difficult the question, or how much it may have been com- 
plicated by imposture, folly, and superstition, this obligation still 
remains. Yet we have men of science, so-called, who rest satis- 
fied with superficial perfunCtory researches, mere apologies for a 
foregone conclusion, and who, on the faith of their own “ edu- 
cated common sense,” adjudicate not merely theories or hypo- 
