l88r.] Geology as a Science and an Art. 455 
is accustomed, too, to be able to determine the data for the 
application of mathematical processes to his problems with 
great accuracy ; so that in his own department his conclu- 
sions have a value that none can dispute. But suppose that 
he takes up such a problem as geological time, the difficulties 
of disentangling the factors of the phenomena and the diffi- 
culties of determining accurate data are so great that his 
conclusions cannot be said to possess anything like the same 
value. Let me, however, quote the words of Dr. Whewell, 
who, as both a mathematician and an historian of science, 
was peculiarly fitted to offer an opinion : — “ A mature con- 
sideration of the subject,” he says, “ will make us hesitate 
to ascribe much value to the labours of those writers who 
have applied mathematical reasoning to geological questions. 
Such reasoning, when it is carried to the extent which re- 
quires symbolical processes, has always been, I conceive, a 
source not of knowledge, but of error and confusion ; for in 
such applications the real questions are slurred over in the 
hypothetical assumptions of the mathematician, while the 
calculation misleads its followers by a false aspect of demon- 
stration.” 
Now the geology of to-day cannot, as I have said, get on 
at all without the aid of chemistry and physics. For all aid 
which she receives from the cultivators of these sciences she 
is heartily thankful. But she does not like to have figures, 
evolved perhaps on insufficient data, crammed down her 
throat, nor does she like the tone of the remark “ Geologists 
must confine their speculations to this period.” 
Leaving this point, let me now proceed to ask another 
question — “ Is there a clear distinction between a Science 
and an Art ; and, if so, of what nature is that distinction ? 
I believe that there is a definite distinction. The objeCt and 
aim of Science is, as I believe, to establish a body of organ- 
ised, and as far as possible exaCt, knowledge : the objeCt and 
aim of Art is to apply the knowledge thus gained to practical 
ends. I think this is a distinction which aids us much in 
getting clear ideas, and I shall therefore illustrate it by an 
example. It is the objeCt of the science of Chemistry to 
ascertain the laws which regulate the combinations and re- 
combinations of the several elements of which all the various 
substances with which we come in daily contact, of which 
everything, in faCt, that is found in the crust of the earth, 
is composed. In the course of his work the chemist has to 
group these various elements, and to separate them one from 
the other. This he does as a scientific man, in order to gain 
knowledge. But he may not improbably come to the 
