256 TRANSACTIONS OF THE PLYMOUTH INSTITUTION. 
Before proceeding to notice the different explanations that have 
been proposed of the pre-existing conditions out of which Life is 
said to have come, it may be useful to see what can be said on the 
other side with respect to this argument from Continuity. For if 
this a priori reasoning is unassailable, the whole case is closed as 
to the general question, though not as to the precise conditions out 
of which in pursuance of Continuity Life evolved. Now, I can 
imagine a thoughtful man taking some such position as this: "You 
say that in the generally admitted Principle of Continuity, as 
understood in modern science, and as now explained by you, 
you find an a priori presumption in favour of your view of the 
origin of Life. Well, I am prepared to admit Continuity, though, 
of course, the real question now is whether it is absolute or 
relative. If it is absolute, universal, of course your view of the 
origin of Life is right. I cannot, however, allow that in this 
argument, because that is the whole question at issue. I grant 
that, in making out Continuity up to the appearance of Life, and 
then Continuity after its appearance, you do make out a very 
strong case — a case which is not to be set aside by a sneer at 
your great knowledge, or any ex cathedra assertion. At the same 
time there are a few suggestions which I would respectfully submit 
for your candid consideration. In the first place, you know how, 
in days gone by, Lord Bacon rather objected to the reasoning of 
Schoolmen because of its being based largely on a priori con- 
siderations ; and, although we live in enlightened times, I am not 
aware that we have quite got rid of the feeling of risk in trusting 
freely to presumptions founded on a priori considerations. They 
are more suited perhaps to the deductive metaphysician than to 
the investigation of natural facts. But, as we are dealing with 
a priori presumptions, may I remind you of a very important fact ; 
namely, that the chief authorities in natural science are one in 
declaring that the law of Nature now is, and all along through the 
pala3ontological ages has been, that Life only comes from Life. 
Now, does not so uniform and steadfast a course of Nature, 
extending over millions of years, raise the counter presumption to 
yours, that the origin of the first Life is certainly not to be sought 
in that which was not living % Do you think it seemly for Nature, 
bearing her numerous children 1 That does not look like Continuity, 
the mother you say of us all, to have two distinct methods of 
in one sense of the word, at least. And if you think that Nature 
