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case to the belief that no form or kind of evolution of living 
beings ever has taken place, or ever will take place. This con- 
clusion would relieve us from any necessity of discussing what 
is known as the “ Darwinian Theory,” since this presupposes 
evolution, and is directly based upon it. 
Secondly, Are might be led to believe that evolution had been 
the general and universal agent in the production of all the 
different forms of animal and vegetable life, which have ex- 
isted in past time, or which exist at the present day. This 
conclusion Avould still leave us under the necessity of discussing 
the Darwinian hypothesis, since this might be false, even if 
the general doctrine of evolution were true. 
Thirdly, avc might be led to the conclusion that certain forms 
of animal and vegetable life had been derived from other pre- 
existent forms, but that certain other forms had not been 
so derived. Now, I Avould here observe that there Avould be 
nothing unphilosophical in such a conclusion, supposing it Avere 
Avarranted by the facts. If there are facts Avhicli Avould go to 
prove that certain animals and plants have been derived from 
certain other animals and plants, avc are Avarranted in adopt- 
ing a derivative theory of origin for these animals and plants, 
but Ave are not Avarranted in doing more than this. Every 
naturalist will admit that the cases in Avhich any direct pro- 
bability of descent can be established, are limited, and com- 
paratively few in number. The Avant of philosophy, therefore, 
if there be any, is on the side of those Avho, taking what at best 
has but been established as a probability in a certain number 
of cases, insist that Ave must manufacture out of this proba- 
bility a general law to apply to all cases. In other Avords, it 
is directly asserted, or tacitly assumed, that if Ave admit that 
certain forms of animal and vegetable life (Avhether Ave choose 
to call these varieties or species) have been derived from 
other pre-existent forms, Ave must further admit that all forms 
of animal and vegetable life have been similarly derived from 
a single pre-existent form, that in turn, being evolved from 
inorganic material. I here protest most strongly against this 
assertion or assumption. It is an absurdity to maintain that 
evolution is either Avholly true or not true at all ; that we must 
either apply the doctrine to everything or to nothing. It is absurd 
to maintain that the admission that certain animals and plants 
have been derived from certain other different animals and 
plants, carries with it, of logical nccessit} 7 , the further admission 
that all animals and plants have been similarly derived. 
Suppose avc find that, as a general rule, bodies contract when 
heat is abstracted from them, are Ave therefore compelled to 
