10 Darwin's Predecessors 
down the opposition which the most scientific had felt to the 
seductive modal formula of evolution by bringing forward a more 
plausible theory of the process than had been previously suggested. 
Nor can one forget, since questions of this magnitude are human 
and not merely academic, that he wrote so that all men could 
understand. 
As Regards the Factors of Evolution. 
It is admitted by all who are acquainted with the history of 
biology that the general idea of organic evolution as expressed in 
the Doctrine of Descent was quite familiar to Darwin’s grandfather, 
and to others before and after him, as we have briefly indicated. It 
must also be admitted that some of these pioneers of evolutionism did 
more than apply the evolution-idea as a modal formula of becoming, 
they began to inquire into the factors in the process. Thus there 
were pre-Darwinian theories of evolution, and to these we must now 
briefly refer’. 
In all biological thinking we have to work with the categories 
Organism—Function—Environment, and theories of evolution may 
be classified in relation to these. To some it has always seemed that 
the fundamental fact is the living organism,—a creative agent, a 
striving will, a changeful Proteus, selecting its environment, adjusting 
itself to it, self-differentiating and self-adaptive. The necessity of 
recognising the importance of the organism is admitted by all 
Darwinians who start with inborn variations, but it is open to 
question whether the whole truth of what we might call the 
aa position is exhausted in the postulate of inherent varia- 
ility. 
To others it has always seemed that the emphasis should be laid 
on Function,—on use and disuse, on doing and not doing. Practice 
makes perfect ; c'est & force de forger qu'on devient forgeron. This 
is one of the fundamental ideas of Lamarckism; to some extent 
it met with Darwin’s approval ; and it finds many supporters to-day. 
One of the ablest of these—Mr Francis Darwin—has recently given 
strong reasons for combining a modernised Lamarckism with what 
we usually regard as sound Darwinism2. 
To others it has always seemed that the emphasis should be laid 
on the Environment, which wakes the organism to action, prompts it 
to change, makes dints upon it, moulds it, prunes it, and finally, 
perhaps, kills it. It is again impossible to doubt that there is truth 
1 See Prof. W. A. Locy’s Biology and its Makers. New York, 1908. Part u. “The 
Doctrine of Organic Evolution.” 
? Presidential Address to the British Association meeting at Dublin in 1908. 
