ON TOE THEORIES OP ELEVATION AND EAHTIIQUAKESi 3/ 
world presents to us, by referring them to the agency of natural causes • but 
in our more extended speculations on geological causation weurenccesskrilv 
dnven to the consideration of the limits beyond which we are compelled tl 
the operation of those higher causes of which physical sciSce can 
questions ol this nature, but before «e can proceed to the examination of 
ilrZrwp'^T^lTl ' on which they are founded, it is esse,,- 
tiiil that we should have some rule for our guidance on ihu noinr TJ.« 
principle I would lay down is this,-That in tilat^ng on The n K phi^^ 
wena which geologj' presents to us a* objects of physical investiwlioii wt 
must refer them to natural causes, so far as it can be proved tint rh* nh ’ 
mena would he the necessary consequences of s"h 
ditions the former existence of which may be deemed aHmkJu n * • 
be™ n 0 fluidit t "-- ■" i'”''' 
system IfOir. the earth, 01 of the matter composing the whole solar 
on iti tK S ■. ^ . f demanded of the theory founded 
existence of explanation of the mmimed 
state of the terrestrial inn* ^ Huolfius as the consequence of a previous 
hypothes s hi hit T ;i contrary, the state axsmned bv this 
wouIdiTmt itElft h 1 hvpo’thesis 
define n ' "‘“P'® w ithout prot -ising to 
S ha^e ber" hypothesis, the terrestrial mass 
tution and form wi,; h ^ receive all the modifications of consti- 
impress upon it un f mechanical causes may have tended to 
state of sfllTdiiv. L i epoch, than if it had always existed in a 
fundamental a^omm-**T *^'?t * hypothesis (considered men ly as a 
one bv tliwA u-h P*'^*0 must I eonceive be preferred to any more restrictive 
mediale^efZo« *T ^hc recognition of secondary causes as the im- 
hcan be*nrnvL ‘"the production of natural phaenomena, whenever 
hy anTeeldZ ^ ^hat I would determine the value of an hypolhesis 
it mav lie nsiderations, independently of the inductive proofs by which 
‘"aj be supported; on the contrary. I would insist on suih proof^ as the 
