ON THE LATEST FORM OF THE DEVELOPMENT THEORY. 115 
of instinct stopped long ago, while the organic structure has advanced from a spider's 
up to a mans. It is not a law of nature, then, that a change of the organism should 
always be accompanied by a change of instinct nicely adapted to it ; consequently, the 
Development Theory can offer no explanation of the fact, that the organism must al-* 
ways have harmonized precisely with the instinct, while the latter was slowly perfected 
by innumerable variations. It is impossible that so nice a correspondence, maintained 
between the two during countless independent changes of each, should have been 
purely accidental or unintentional.* 
Those who deny that there has been any special act of creation since living forms 
first appeared upon the earth, are bound, of course, to account for the origin of the 
human species, just as much as for that of the lowest insect. Mr. Darwin confesses as 
much when he says that, after the general reception of his system, * 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 upon the origin of man and his 
. history." (p. 423.) He is bound, therefore, to find the means of bridging over, by 
innumerable slight gradations, the immense gap which now separates man from the 
animals most nearly allied to him, — a gap not only between the two structural forms, 
which, however dissimilar, may still be affirmed to be of the same kind, but between 
reason and instinct, where nearly all psychologists are agreed that the difference is 
in kind, and not merely in degree. As Sir C. Lyell remarks, “the sudden passage 
from an irrational to a rational animal is a phenomenon of a distinct kind from the 
passage from the more simple to the more perfect forms of animal E EN and 
instinct" T cj 
Here an didam objection occurs, founded upon the comparative ion of the 
time during which man has been a resident upon the earth. “Man,” says Lyell, 
« must be regarded by the geologist as a creature of yesterday, not merely in reference 
to the past history of the organic world, but also in relation to that particular state of 
the animate creation of which he forms a part.” { Even the questionable evidence 
recently obtained from the discovery of flint knives and arrow-heads in localities where 
their presence is difficult to be accounted for, does not enable us to ascribe to the 
human race a higher antiquity than that of the later post-Tertiary formations. Then 
the interval of time, within which far the broadest chasm which we have to contem- 
* Here, and elsewhere i in this Memoir, a few remarks have been repeated, i in an abridged form, which were 
first published in an article contributed by me to the North American Review for April, 1860. 
+ Lyell’s Principles of Geology, Am. ed. 1853, p. 148. 
-1 Ibid, p. 182. ` a 
