400 FRAGMENTS OF SCIENCE. 
Partly through mathematical and partly through experi- 
mental research, physical science has, of late years, 
assumed a momentous position in the world. Both in a 
material and in an intellectual point of view it has pro- 
duced, and it is destined to produce, immense changes 
vast social ameliorations, and vast alterations in the popular 
conception of the origin, rule, and governance of natural 
tilings. By science, in the physical world, miracles are 
wrought, while philosophy is forsaking its aticient meta- 
physical channels, and pursuing others which have been 
opened, or indicated by scientific research. This must 
become more and more the case as philosophical writers 
become more deeply imbued with the methods of science, 
better acquainted with the facts which scientific men have 
established, and with the great theories which they have 
elaborated. 
If you look at the face of a watch, you see the hour and 
minute-hands, and possibly also a second-hand, moving 
over the graduated dial. Why do these hands move? and 
why are their relative motions such as they are observed to 
be? These questions cannot be answered without opening 
the watch, mastering its various parts, and ascertaining 
their relationship to each other. When this is done, we 
find that the observed motion of the hands follows of 
necessity from the inner mechanism of the watch when 
acted upon by the force invested in the spring. The 
motion of the hands may be called a phenomenon of art, 
but the case is similar with the phenomena of nature. 
These also have their inner mechanism and their store of 
force to set that mechanism going. The ultimate problem 
of physical science is to reveal this mechanism, to discern 
this store, and to show that from the combined action of 
both, the phenomena of which they constitute the basis, 
must, of necessity, flow. 
I thought an attempt to give you even a brief and sketchy 
illustration of the manner in which scientific thinkers 
regard this problem would not be uninteresting to you on 
the present occasion; more especially as it will give me 
occasion to say a word or two on the tendencies and limits 
of modern science; to point out the region which men of 
science claim as their own, and where it is futile to oppose 
their advance; and also to define, if possible, the bourne 
between this and that other region, to which the question- 
