―18―“The relations, dependencies, and connections of the several
parts of knowledge, have long been a subject of unavailing inqui-
ry with me. In my late commenced correspondence with Eme-
lius, this was the question upon which I demanded his opinion:
he has not yet returned an answer to my letter, though from
his expressions at the meeting at Franklin's, I judge he had some
serious intentions of answering it. The carrying into effect this
scheme of a society, will I am afraid be to him a sufficient ex-
cuse for omitting it. I now intend to try what my own unassist-
ed capacity can do towards classing and separating the several
departments of knowledge. However, to my task.
“The general and I believe the true division of science, is into
moral and physical. The object of moral science is the mind,
the object of physical, matter: this is sufficiently plain. I under-
stand the distinction between matter and mind, or spirit (for they
are synonymous) without the trouble of a definition.
“Mind and matter are the two grand divisions of science,
but we cannot have any object of moral science, but that portion
of spirit within ourselves; while in this life mind perhaps can
never be considered in any other way than in conjunction with
matter. That science which considers mind in its essence, which
considers spirit distinct from, and as much as possible indepen-
dant of matter, is I think called metaphysics. Is there not a dif-
ference between the consideration of the mind in its essence or
being, and the consideration of the mind, as it acts with rela-
tion to something else, just as we consider man in the several
lights of a rational creature, and as a member of society? We
know that our minds are continually employed in the exercise of
apprehension, reason, and will: but we know that these operations
of the mind are employed upon things outward and foreign to
itself. When we view it in these operations, I think we do not
view as metaphysicians, we must give another name to the sci-
ence; perhaps it is logic. Man may be considered in a variety
of lights, the distinction between physical and moral science take
their rise in him; he is a creature of matter and mind composed
―19―
in newly organized matter; he is superior to the brutes only in
degree, and he is equally with them, the object of physical sci-
ence; but in mind he differs from them originally and in kind. He
is therefore the only subject of moral science: as an animal he is
the subject of natural history. What is anatomy? Is it not natu-
ral history? It examines his internal structure and formation: what
is this but natural history? all animals are the subjects of anato-
my, perhaps all substances: the dissection of a rabbit and the reso-
lution of a metallic substance, are they not equally anatomy, only
the instrument made use of is fire in one, and the lancet in
the other? However chemistry is only a more exact and thorough
anatomy. Chemistry and anatomy therefore are nearly allied,
their object is the same, their difference consists only in the differ-
ent nature of the things on which they operate, and they are both
ranked under the science of natural history. Man as an animal
is the subject of the science of medicine, which is nothing more
than the art of curing diseases incident to the human body. But
there are diseases incident to the mind also; is the cure of these
the province of the physician, when the mind is affected by the
disorders of the animal system, or when its diseases may be cured,
by the application of external remedies. It is thus the province of
the physician. It is necessary for a physician to be an anatomist,
that is, the natural historian of man; because the knowledge of
his interior formations may lead him to the source or cause of
the diseases incident to him. It may be a question whether the
experimental mode in physic, that is the theory of disease drawn
from anatomy, is equally advantageous to the cause of true
science, as the same mode in the other part of natural philosophy.
But I am not physician enough to know whether I speak pro-
perly.
“Man, as I said before, as an animal, is the object of medicine;
but there are other animals besides; the science of medicine
therefore is not confined to him only. But why is the cow doc-
tor, the horse doctor considered so meanly of then: 1, because the
diseases of other animals are less numerous and complicated: 2,
because the life or health of a brute is of much less importance in
the eye of man than the life or health of his fellow creature, and
the diseases of men are more new and difficult, because of the
―20―
connection between his mind and his body, and the mutual in-
fluence they have upon each other.
“The consideration of the internal structure of man, with re-
ference to the internal structure of other animals, or vice versa, is
called comparative anatomy.
“Man possesses five senses or inlets to his mind. Of these
the sight is the most useful, extensive and delicate in its forma-
tion. Optics is that science which explains the theory of light
and colours, and describes the manner in which outward objects
affect the sight. The science of the occulist consists in the know-
ledge of the cure of the diseases incident to the eye. The
importance of sight to men, and the exquisite organization of that
matter in which it is centered, demand and have a separate theory.
The teeth also, though none of the senses, from their usefulness
in mastication, but principally from the addition which when per-
fect they are supposed to contribute to the beauty of the hu-
man face, employ, though undeservedly, a separate profession.
Man may be considered as one, and alone; or he may be con-
sidered as a member of a community, and connected with
others.”