BOOK II PART I
the rest, pride and humility, are derived solely
from that origin. Such simple and natural prin-
ciples, founded on such solid proofs, cannot
fail to be received by philosophers, unless op-
posed by some objections, that have escaped
me.
It is usual with anatomists to join their ob-
servations and experiments on human bodies
to those on beasts, and from the agreement of
these experiments to derive an additional argu-
ment for any particular hypothesis. It is indeed
certain, that where the structure of parts in
brutes is the same as in men, and the operation
of these parts also the same, the causes of that
operation cannot be different, and that what-
ever we discover to be true of the one species,
may be concluded without hesitation to be cer-
tain of the other. Thus though the mixture of