27. Nominal essences of particular substances are undetermined by nature, and therefore various as men vary.
Wherein, then, would I gladly know, consist the precise and unmovable boundaries of that species? It is plain, if
we examine, there is no such thing made by Nature, and established by her amongst men. The real essence of that
or any other sort of substances, it is evident, we know not; and therefore are so undetermined in our nominal
essences, which we make ourselves, that, if several men were to be asked concerning some oddly shaped fœtus,
as soon as born, whether it were a man or no, it is past doubt one should meet with different answers. Which
could not happen, if the nominal essences, whereby we limit and distinguish the species of substances, were not
made by man with some liberty; but were exactly copied from precise boundaries set by nature, whereby it
distinguished all substances into certain species. Who would undertake to resolve what species that monster was
of which is mentioned by Licetus (Bk. i. c. 3), with a man's head and hog's body? Or those other which to the
bodies of men had the heads of beasts, as dogs, horses, etc. If any of these creatures had lived, and could have
spoke, it would have increased the difficulty. Had the upper part to the middle been of human shape, and all
below swine, had it been murder to destroy it? Or must the bishop have been consulted, whether it were man
enough to be admitted to the font or no? As I have been told it happened in France some years since, in somewhat
a like case. So uncertain are the boundaries of species of animals to us, who have no other measures than the
complex ideas of our own collecting: and so far are we from certainly knowing what a man is; though perhaps it
will be judged great ignorance to make any doubt about it. And yet I think I may say, that the certain boundaries
of that species are so far from being determined, and the precise number of simple ideas which make the nominal
essence so far from being settled and perfectly known, that very material doubts may still arise about it. And I
imagine none of the definitions of the word man which we yet have, nor descriptions of that sort of animal, are so
perfect and exact as to satisfy a considerate inquisitive person; much less to obtain a general consent, and to be
that which men would everywhere stick by, in the decision of cases, and determining of life and death, baptism or
no baptism, in productions that might happen.