much a man may be convinced of the correctness of his evidence,
he may yet fail in the face of the doubting judge to know anything
certainly?

Now one of the most difficult tasks of the criminalist is to hit,
in just such cases, upon the truth; neither to accept the testimony
blindly and uncritically; nor to render the witness, who otherwise

is telling the truth, vacillating and doubtful. But it is still more
difficult to lead the witness, who is not intentionally falsifying, but
has merely observed incorrectly or has made false conclusions, to a
statement of the truth as Socrates leads the slave in the Meno.
It is as modern as it is comfortable to assert that this is not the
judge's business--that the witness is to depose, his evidence is to
be accepted, and the judge is to judge. Yet it is supposed before
everything else that the duty of the court is to establish the material
truth--that the formal truth is insufficient. Moreover, if we notice
false observations and let them by, then, under certain circumstance,
we are minus one important piece of evidence _*pro_ and _*con_,
and the whole case may be turned topsy turvy. At the very least
a basis of development in the presentation of evidence is so excluded.
We shall, then, proceed in the Socratic fashion. But, inasmuch as
we are not concerned with mathematics, and are hence more badly
placed in the matter of proof, we shall have to proceed more cautiously
and with less certainty, than when the question is merely
one of the area of a square. On the one hand we know only in the
rarest cases that we are not ourselves mistaken, so that we must
not, without anything further, lead another to agree with us; on
the other hand we must beware of perverting the witness from his
possibly sound opinions. It is not desirable to speak of suggestion