30 
LE CONTE. 
Thus, then, as the line between mineral and organic chem¬ 
istry was more and more effaced, the line between chemistry 
and physiology became clearer and clearer, chemistry claim¬ 
ing all dead matter and physiology all the living. The mu¬ 
tual claims of these two sciences may be said now to be per¬ 
manently adjusted. There is, of course, a chemistry in the 
living body, but it is chemistry under the control of a higher 
force—life. It is true that both physics and chemistry un¬ 
derlie and condition life; but life-phenomena are a peculiar 
group; so peculiar and so different from pure chemical and 
physical phenomena that they constitute the subject-matter 
of a very distinct department of science.* It is worthy of 
remark that this is only a return, after a long scientific de¬ 
tour, to the original and most obvious point of view, for 
popular intuition has always recognized the great gap be¬ 
tween the living and the dead. Thus in many ways Science 
verifies our intuitions. This, in fact, is the most important 
function of science. 
* It will be observed that all through this article I use the words vitality , 
vital force , life-force. Now, I know that this expression is often ridiculed 
as a remnant of superstition. It has even been wittily said that we might 
as well speak of aquosity as determining the properties of water as of vitality 
as determining the phenomena of living organisms. Such objectors are 
partly right and partly wrong. The old idea of vitality was that of a force 
standing above natural forces and controlling them, and thus in some 
sense supernatural and unrelated to other forms of force. This idea is 
untenable. Vital force is correlated with, derivable from, transmutable 
into, physical and chemical forces, and no one has insisted on this more 
than I have; but it is none the less a very distinct form of force, more 
distinct from them than they are from one another, giving rise to a veiy 
peculiar group of phenomena, which constitutes the subject-matter of a 
very distinct department of science, more distinct than any other lower 
department. As long as we use names for other forms of force, as gravity, 
electricity, chemical affinity, &c., much more ought we to use a name, 
vitality , to group the phenomena characteristic of living things. If it be 
asked, Why not then aquosity for the force inherent in water ? I answer: 
This does not group phenomena belonging to an infinite variety of bodies. 
Affinity or chemism is the proper word here. 
