gin of evil, seems, as I have said, not
to be given to man fully to comprehend.

"The different races of mankind," says Humboldt, employing, let me
remark, the language of the distinguished German naturalist Mueller, to
give expression to the view which he himself adopts,--"the different
races of mankind are not different species of a genus, but forms of one
sole species." "The human species," says Cuvier, "appears to be single."
"When we compare," says Pritchard, "all the facts and observations which
have been heretofore fully established as to the specific instincts and
separate psychical endowments of all the distinct tribes of sentient
beings in the universe, we are entitled to draw confidently the
conclusion, that all human races are of one species and one family."
"God hath made of one blood," said the Apostle Paul, in addressing
himself to the _elite_ of Athens, "all nations, for to dwell on the face
of all the earth." Such, on this special head, is the testimony of
Revelation, and such the conclusion of our highest scientific
authorities. The question has, indeed, been raised in these latter
times, whether each species of animals may not have been originally
created, not by single pairs or in single centres, but by several pairs
and in several centres, and, of course, the human species among the
rest? And the _query_,--for in reality it amounts to nothing more,--has
been favorably entertained on the other side of the Atlantic. On purely
scientific grounds it is of course difficult to prove a negative in the
case, just as it would be difficult to prove a negative were the
question to be, whether the planet Venus was not composed of quartz
rock, or the planet Mars of Old Red Sandstone? But the portion of the
problem really solvable by science,--the identity of the human race
under all its conditions, and in all its varieties,--science _has_
solved. It has determined that all the various tribes of man are but
forms of a single species. And in the definition of species,--waiving
the American _doubt_ until it shall at least become something more,--I
am content to follow the higher authorities. "We unite," says M. de
Candolle, "under the designation of a _species_, all those individuals
that mutually bear to each other so close a resemblance as to allow of
our supposing that they may have proceeded originally from a single
being or a single pair." "A _species_," says Buffon, "is a constant
succession of individuals si