382 Darwin and: Geology 
opinion of younger men, their enthusiasm for science, their freedom 
from petty jealousies and their righteous indignation for what was 
mean and unworthy in others. But yet there was a difference. Both 
Lyell and Darwin were cautious, but perhaps Lyell carried his 
caution to the verge of timidity. I think Darwin possessed, and 
Lyell lacked, what I can only describe by the theological term, 
“faith—the substance of things hoped for, the evidence of things 
not seen.” Both had been constrained to feel that the immutability 
of species could not be maintained. Both, too, recognised the fact 
that it would be useless to proclaim this conviction, unless prepared 
with a satisfactory alternative to what Huxley called “the Miltonic 
hypothesis.” But Darwin’s conviction was so far vital and operative 
that it sustained him while working unceasingly for twenty-two 
years in collecting evidence bearing on the question, till at last he 
was in the position of being able to justify that conviction to others, 
And yet Lyell’s attitude—and that of Hooker, which was very 
similar—proved of inestimable service to science, as Darwin often 
acknowledged. One of the greatest merits of the Origin of Species 
is that so many difliculties and objections are anticipated and fairly 
met; and this was to a great extent the result of the persistent 
and very candid—if always friendly—criticism of Lyell and Hooker. 
I think the divergence of mental attitude in Lyell and Darwin 
must be attributed to a difference in temperament, the evidence of 
which sometimes appears in a very striking manner in their corre- 
spondence. Thus in 1838, while they were in the thick of the fight 
with the Catastrophists of the Geological Society, Lyell wrote 
characteristically: “I really find, when bringing up my Preliminary 
Essays in Principles to the science of the present day, so far as 
I know it, that the great outline, and even most of the details, stand 
so uninjured, and in many cases they are so much strengthened by 
new discoveries, especially by yours, that we may begin to hope that 
the great principles there insisted on will stand the test of new dis- 
coveries'.” To which the more youthful and impetuous Darwin replies: 
“Begin to hope: why the possibility of a doubt has never crossed 
my mind for many a day. This may be very unphilosophical, but my 
geological salvation is staked on it...it makes me quite indignant that 
you should talk of hoping?.” 
It was not only Darwin’s “geological salvation” that was at stake, 
when he surrendered himself to his enthusiasm for an idea. To his 
firm faith in the doctrine of continuity we owe the Origin of Species; 
and while Darwin became the “Paul” of evolution, Lyell long re- 
mained the “doubting Thomas.” 
Many must have felt like H. C. Watson when he wrote: “How 
1 Lyell’s Life, Letters and Journals, Vol. 1. p. 44. 21. L. 1 p. 296. 
