such evidence implied, as has been
said, an elementary knowledge of toxicology.

Coupled with this knowledge of things dangerous to the human system,
there must have grown up, at a very early day, a belief in the remedial
character of various vegetables as agents to combat disease. Here,
of course, was a rudimentary therapeutics, a crude principle of an
empirical art of medicine. As just suggested, the lower order of animals
have an instinctive knowledge that enables them to seek out remedial
herbs (though we probably exaggerate the extent of this instinctive
knowledge); and if this be true, man must have inherited from his
prehuman ancestors this instinct along with the others. That he extended
this knowledge through observation and practice, and came early to make
extensive use of drugs in the treatment of disease, is placed beyond
cavil through the observation of the various existing barbaric tribes,
nearly all of whom practice elaborate systems of therapeutics. We shall
have occasion to see that even within historic times the particular
therapeutic measures employed were often crude, and, as we are
accustomed to say, unscientific; but even the crudest of them are really
based upon scientific principles, inasmuch as their application implies
the deduction of principles of action from previous observations.
Certain drugs are applied to appease certain symptoms of disease because
in the belief of the medicine-man such drugs have proved beneficial in
previous similar cases.

All this, however, implies an appreciation of the fact that man is
subject to "natural" diseases, and that if these diseases are not
combated, death may result. But it should be understood that the
earliest man probably had no such conception as this. Throughout all the
ages of early development, what we call "natural" disease and "natural"
death meant the onslaught of a tangible enemy. A study of this question
leads us to some very curious inferences. The more we look into the
matter the more the thought forces itself home to us that the idea
of natural death, as we now conceive it, came to primitive man as
a relatively late scientific induction. This thought seems almost
startling, so axiomatic has the conception "man is mortal" come to
appear. Yet a study of the ideas of existing savages, combined with
our knowledge of the point of view from which historical peoples regard
disease, make it more probable that the primitive conception of human
li