376 THE CAUSES OF THE XI 
conclusions and theories.1. Having granted that 
the inquiry is a proper one, and having determined 
on the nature of the methods we are to pursue 
and which only can lead to success, [ must now 
turn to the consideration of our knowledge of the 
nature of the processes which have resulted in the 
present condition of organic nature. 
Here, let me say at once, lest some of you mis- 
understand me, that I have extremely little to 
report. The question of how the present condition 
of organic nature came about, resolves itself into 
two questions. The first is: How has organic or 
living matter commenced its existence? And the 
second is : How has it been perpetuated? On the 
second question I shall have more to say hereafter. 
But on the first one, what I now have to say will 
be for the most part of a negative character. 
If you consider what kind of evidence we can 
have upon this matter, it will resolve itself into 
two kinds. We may have historical evidence and we 
may have experimental evidence. It is, for example, 
conceivable, that inasmuch as the hardened mud 
which forms a considerable portion of the thick- 
ness of the earth’s crust contains faithful records 
of the past forms of life, and inasmuch as these — 
differ more and more as we go further down,—it — 
is possible and conceivable that we might come to ~ 
1 Those who wish to study fully the doctrines of which I | 
have endeavoured to give some rough-and-ready illustrations, 
must read Mr. John Stuart Mill’s System of Logic. 
