i6o CiayfcU'. c-i: 'Dai-tvin ^iiui Gedcgy. 
limited time, and that no world-wide catastrophe has e\ er oc- 
cured to break the chain. After contrasting at considerable 
length his own views with those of his predecessors he re- 
marks: 
It appears clear that the earlier geologists had not only a ^^canty 
acquaintance with existing changes, but were singularly unconscious of 
the amount of their ignorance. With the presumption naturally inspired 
by this unconsciousness they had no hesitation in deciding at once that 
time could never enable the existing forces of nature to work out changes 
of great magnitude, still less so important revolutions as are those 
brought to light by geology. They therefore thought themselves justified 
in indulging their imagination in guessing what might be rather than in 
inquiring what is. The course directly opposed to this method of philos- 
ophizing consists of an earnest and patient study how far geological ap- 
pearances are reconcilable with the effect of changes now in progress. 
It also endeavours to estimate the aggregate result of ordinary operations 
multiplied by time. For this reason all theories are rejected which in- 
volve the assumption of sudden and violent catastrophes and revolutions 
of the earth and its inhabitants. Princlj'les, 1S53, p. 196. 
This was the school of geology on which no longer than 
thirt}' years ago, theology had laid its ban, and which it de- 
nounced for heterodoxy. 
It is exceedingly interesting and instructive at this point to 
i»]iser\e the attitude of the great master of the uniformitarian 
school. While boldlv maintaining in the face of strong and form- 
idal)le opponents his theory of the slow and regular development 
of *the earth's geograph}-, he hesitates over the application of 
the same principle to the organic world. The outspoken advo- 
cate here becomes a feeble and insinuating apologist. On the 
question of geography Lyell gives no uncertain sountl, but 
in the case of biology his notes are shaky. After ranging 
freeh' o^'er whole continents of inorganic change he halts sud- 
denl}-, irresolute and staggering, on the brink of the chaotic 
abyss that opened before him when he began to treat of chang- 
es oi-ganic. It is almost amusing to contrast the confident tone 
of the great teacher on the former with his uncertain utterances 
on the latter. In his "Principles," (Ed. 1853) the greater 
part of which is given to a discussion in maintenance of his views 
on inorganic development, he passes on, toward the close, to con- 
sideration of the fixity or mutability of species. After a long 
