of the criminal judge. Whether it arises with regard to the
accused, the witness, the associate justice, or the expert, is all one;
it is invariably the same.

That knowledge of human nature is for this purpose most important
to the criminalist will be as little challenged as the circumstance
that such knowledge can not be acquired from books. Curiously
enough, there are not a few on the subject, but I suspect that
whoever studies or memorizes them, (such books as Pockel's,
Herz's, Meister's, Engel's, Jassoix's, and others, enumerated by
Volkmar) will have gained little that is of use. A knowledge of
human nature is acquired only (barring of course a certain talent
thereto) by persevering observation, comparison, summarization,
and further comparison. So acquired, it sets its possessor to the
fore, and makes him independent of a mass of information with
which the others have to repair their ignorance of mankind. This
is to be observed in countless cases in our profession. Whoever has
had to deal with certain sorts of swindlers, lying horsetraders,
antiquarians, prestidigitators, soon comes to the remarkable conclusion,
that of this class, exactly those who flourish most in their profession
and really get rich understand their trade the least. The horsedealer
is no connoisseur whatever in horses, the antiquarian can not
judge the value nor the age and excellence of antiquities, the cardsharp
knows a few stupid tricks with which, one might think, he
ought to be able to deceive only the most innocent persons. Nevertheless
they all have comfortable incomes, and merely because they
know their fellows and have practiced this knowledge with repeatedly
fresh applications.

I do not of course assert that we criminalists need little scholarly