Section I. (a) General Considerations.
SOCRATES, dealing in the Meno with the teachability of virtue,
sends for one of Meno's slaves, to prove by him the possibility of
absolutely certain a priori knowledge. The slave is to determine the
length of a rectangle, the contents of which is twice that of one
measuring two feet; but he is to have no previous knowledge of the
matter, and is not to be directly coached by Socrates. He is to
discover the answer for himself. Actually the slave first gives out
an incorrect answer. He answers that the length of a rectangle
having twice the area of the one mentioned is four feet, thinking
that the length doubles with the area. Thereupon Socrates triumphantly
points out to Meno that the slave does as a matter of
fact not yet quite know the truth under consideration, but that he
really thinks he knows it; and then Socrates, in his own Socratic
way, leads the slave to the correct solution. This very significant
procedure of the philosopher is cited by
Guggenheim[1] as an
illustration of the essence of a priori knowledge, and when we properly
consider what we have to do with a witness who has to relate
any fact, we may see in the Socratic method the simplest example
of our task. We must never forget that the majority of mankind
dealing with any subject whatever always believe that they know and
repeat the truth, and even when they say doubtfully: "I believe.—
It seems to me," there is, in this tentativeness, more meant than
meets the ear. When anybody says: "I believe that—" it merely
means that he intends to insure himself against the event of being
contradicted by better informed persons; but he certainly has not
the doubt his expression indicates. When, however, the report of
some bare fact is in question ("It rained," "It was 9 o'clock,"
"His beard was brown," or "It was 8 o'clock,") it does not matter
to the narrator, and if he imparts
such facts with
the introduction,
"I believe," then he was really uncertain. The matter becomes
important only where the issue involves partly-concealed observations,
conclusions and judgments. In such cases another factor
enters—conceit; what the witness asserts he is fairly certain of
just because he asserts it, and all the "I believes," "Perhapses,"
and "It seemeds," are merely insurance against all accidents.
Generally statements are made without such reservations and,
even if the matter is not long certain, with full assurance. What
thus holds of the daily life, holds also, and more intensely, of
court-witnesses, particularly in crucial matters. Anybody experienced
in their conduct comes to be absolutely convinced that witnesses
do not know what they know. A series of assertions are made
with utter certainty. Yet when these are successively subjected to
closer examinations, tested for their ground and source, only a very
small portion can be retained unaltered. Of course, one may here
overshoot the mark. It often happens, even in the routine of daily
life, that a man may be made to feel shaky in his most absolute
convictions, by means of an energetic attack and searching questions.
Conscientious and sanguine people are particularly easy subjects
of such doubts. Somebody narrates an event; questioning begins
as to the indubitability of the fact, as to the exclusion of possible
deception; the narrator becomes uncertain, he recalls that, because
of a lively imagination, he has already believed himself to have
seen things otherwise than they actually were, and finally he admits
that the matter might probably have been different. During trials
this is still more frequent. The circumstance of being in court of
itself excites most people; the consciousness that one's statement is,
or may be, of great significance increases the excitement; and the
authoritative character of the official subdues very many people
to conform their opinions to his. What wonder then, that however
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
proand
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
in this matter, since, if I believe that the other fellow knows a matter
better than I and conform to his opinion, there is as yet no suggestion.
And this pure form of change of opinion and of openness to
conviction is commonest among us. Whoever is able to correct
the witness's apparently false conceptions and to lead him to discover
his error of his own accord and then to speak the truth—
whoever can do this and yet does not go too far, deducing from the
facts nothing that does not actually follow from them—that man
is a master among us.
[[1]]
M. Guggenheim: Die Lehre vom
aprioristischen Wissen. Berlin 1885.