THE 
JOURNAL OF SCIENCE. 
JULY, 1880. 
I. THE EVOLUTION OF SCIENTIFIC 
KNOWLEDGE. 
By C. Lloyd Morgan. 
t 5 " N the “ Westminster Review ” for April, 1857, appeared 
an Essay on “ Progress : its Law and Cause,” by Mr. 
Herbert Spencer, in which was first sketched the Law 
of Evolution more fully developed in the First Principles. 
Of that law the late Prof. Clifford said, some twelve years 
a^o that “ it is to the ideas which preceded it even more 
than the theory of gravitation was to the guesses of Hooke 
and the fadts of Kepler.” And now it seems almost an im- 
pertinence to the reader to occupy any space here with a 
definition of this Law of Evolution. Still, impertinence 
though it be, I venture to preface what I have to say on the 
Evolution of Scientific Knowledge with a few words on the 
general law, by way of reminder. The processes of Evolu- 
tion, according to Mr. Herbert Spencer, are processes of 
differentiation and integration ; that is to say, they are pro- 
cesses by which the parts of that which is being evolved 
become more different, and by which those parts, at the 
same time, become more dependent upon each other, and are 
bound together into a more definite, complex whole. Where, 
as in most cases, Evolution is accompanied by growth, the 
differentiation and integration are not confined to the pai ts 
which originally existed in the system, but are extended to 
the material which is gradually incorporated with the ori- 
ginal matter. And where, as is always more or less the 
case the parts of the evolving system are in motion, this 
motion also is subject to the processes of integration and 
differentiation. 
VOL. II. (THIRD SERIES). 8 G 
