ure has for
the most part left us nothing at our disposal for establishing
distinctions, save trifling, and in some respects puerile
particularities. We find that many genera among plants and animals are
of such an extent, in consequence of the number of species referred to
them, that the study and determination of these last have become almost
impracticable. When the species are arranged in a series, and placed
near to each other, with a due regard to their natural affinities, they
each differ in so minute a degree from those next adjoining, that they
almost melt into each other, and are in a manner confounded together. If
we see isolated species, we may presume the absence of some more closely
connected, and which have not yet been discovered. Already there are
genera, and even entire orders, nay, whole classes which present this
state of things." He then goes on to present, "as a guide to
conjecture," what his successors now assert as a fact: "In the first
place, if we examine the whole series of known animals, from one
extremity to the other, when they are arranged in the order of their
natural relations, we find that we may pass progressively, or at least
with very few interruptions, from beings of more simple to those of more
compound structure; and in proportion as the complexity of their
organization increases, the number and dignity of their faculties
increase also. Among plants a similar approximation to a graduated scale
of being is apparent. Secondly, it appears, from geological
observations, that plants and animals of more simple organization
existed on the globe before the appearance of those of more compound
structure, and the latter were successively formed at more modern
periods, each new race being more fully developed than the most perfect
of the preceding one."[22]

From this gradation of nature, thus stated, the evolutionists go on to
infer genealogy, the birth descent of the larger from the smaller, and
of the more complex from the simpler forms, as the only scientific
explanation. But it is by no means the only scientific explanation of
the order of nature. The best naturalists, from Moses to Agassiz, have
regarded the order of nature as the development of the divine idea, have
prosecuted their researches on that view, and have regarded that as a
sufficient and scientific explanation of the gradation of plants and
animals, as they actually exist.

The idea of birth descent can not be logically c