§20 ANNIVERSARY ADDRESS TO THE GEOLOGICAL SOCIETY 
genera and species, which we ascribe to new creation, may be simple 
results of migration. 
It may be so; it may be otherwise. In the present condition of 
our knowledge and of our methods, one verdict—* not proven, and 
not proveable’’—must be recorded against all the grand hypotheses 
of the paleontologist respecting the general succession of life on 
the globe. The order and nature of terrestrial life as a whole are 
open questions. Geology at present provides us with most valuable 
topographical records, but she has not the means of working them 
up into a universal! history. Is such a universal history, then, to 
be regarded as unattainable? Are all the grandest and most 
interesting problems which offer themselves to the geological 
student essentially insoluble? Is he in the position of a scientific 
Tantalus—doomed always to thirst for a knowledge which he 
cannot obtain? The reverse is to be hoped; nay, it may not be 
impossible to indicate the source whence help will come. 
In commencing these remarks, mention was made of the great 
obligations under which the naturalist lies to the geologist and 
paleontologist. Assuredly the time will come when these obliga- 
tions will be repaid tenfold, and when the maze of the world’s past 
history, through which the pure geologist and the pure palaonto- 
logist find no guidance, will be securely threaded by the clue fur- 
nished by the naturalist. 
All who are competent to express an opinion on the subject are 
at present agreed that the manifold varieties of animal and vegetable 
form have not either come into existence by chance, nor result from 
capricious exertions of creative power ; but that they have taken place 
in a definite order, the statement of which order is what men of science 
term a natural law. Whether such a law is to be regarded as an 
expression of the mode of operation of natural forces, or whether 
it is simply a statement of the manner in which a supernatural 
power has thought fit to act is a secondary question, so long as 
the existence of the law and the possibility of its discovery by the 
human intellect are granted. But he must be a half-hearted philo- 
sopher who, believing in that possibility, and having watched the 
gigantic strides of the biological sciences during the last twenty 
years, doubts that science will sooner or later make this further step 
so as to become possessed of the law of evolution of organic forms— 
of the unvarying order of that great chain of causes and effects of 
which all organic forms, ancient and modern, are the links. And 
then, if ever, we shall be able to begin to discuss with profit 
the questions respecting the commencement of life, and the nature of 
