Chap. XIV. 
COXCLUSIOX. 
489 
important researches. Psychology will be based on a 
new foundation, that of the necessary acquirement of 
each mental power and capacity by gradation. Light 
will be thrown on the origin of man and his history. 
Authors of the highest eminence seem to be fully 
satisfied with the view that each species has been inde¬ 
pendently created. To my mind it accords better with 
what we know of the laws impressed on matter by the 
Creator, that the production and extinction of the past 
and present inhabitants of the world should have been 
due to secondary causes, like those determining the 
birth and death of the individual. When I view all 
beings not as special creations, but as the lineal de¬ 
scendants of some few beings which lived long before the 
first bed of the Silurian system was deposited, they seem 
to me to become ennobled. Judging from the past, we 
may safely infer that not one living species will trans¬ 
mit its unaltered likeness to a distant futurity. And of 
the species now living very few will transmit progeny 
of any kind to a far distant futurity; for the manner in 
which all organic beings are grouped, shows that the 
greater number of species of each genus, and all the 
species of many genera, have left no descendants, but 
have become utterly extinct. We can so far take a 
prophetic glance into futurity as to foretel that it will 
be the common and widely-spread species, belonging to 
the larger and dominant groups, which will ultimately 
prevail and procreate new and dominant species. As 
all the living forms of life are the lineal descendants of 
those which lived long before the Silurian epoch, we 
may feel certain that the ordinary succession by genera¬ 
tion has never once been broken, and that no cataclysm 
has desolated the whole world. Hence we may look 
with some confidence to a secure future of equally in¬ 
appreciable length. And as natural selection works 
y 3 
