gress, that such unnatural modes of life as conduce to their
production, would take place.

As the first professors of physic knew nothing of the animal economy,
and little of the theory of diseases, it is evident that whatever
they did, must have been in consequence of mere random trials. Indeed
it is impossible that this or any other art could originate in any
other manner. Accordingly history informs us that the ancient nations
used to expose their sick in temples, and by the sides of highways,
that they might receive the advice of every one that passed.

It would take up too much time to pursue the history of medicine from
this rude origin, through all its changes and revolutions, till the
present time: let it therefore suffice to say, that after various
theories had been invented and overturned, and after one age had
destroyed the labours of another, though different branches of the
healing art, and particularly anatomy, had been enriched with
valuable discoveries, still a rational theory was wanting; there was
nothing to guide the practitioner in his way, and we may truly say
that till the laws of life, which I have been endeavouring to
illustrate, were investigated by Dr. Brown, medicine could boast of
no theory which had a title to be called philosophical.

The theories of Stahl, Boerhaave, and Cullen, have passed away, and
are almost forgotten, but this, which is founded on nature, and on
fact, will, like the Newtonian philosophy, last for ever. It has
already influenced the practice of medicine, and is taught in almost
all the schools of Europe and America. In this country it seems to
have had less attention paid to it than it deserved, because its
influence was counteracted by the arrogance and profligacy of its
author, as if the grossness of a man's manner affected the
conclusiveness of his arguments; but this influence did not extend
beyond Britain, while the light of his theory illuminated the
opposite hemisphere. And when the manner in which he was persecuted
is recollected, the liberal mind will allow something to the deep
consciousness of neglected merit.

A circumstance much in favour of this doctrine is, that those who
understand its principles thoroughly, are guided by it in their
practice with a certainty and success before unknown. I say those who
understand its principles, for these were not perfectly understood
even by the author himself. He first saw with his mind's eye the
grand outline of