An ignoramus is ineligible for a witness.
The following are ineligible as witnesses of the appearance of the new
moon:--Dice-players, usurers, pigeon-fliers, sellers of the produce of
the year of release, and slaves. This is the general rule; in any case
in which women are inadmissible as witnesses, they also are inadmissible
here.
_Rosh Hashanah_, fol. 22, col. 1.
Two disciples of the wise happened to be shipwrecked with Rabbi Yossi
ben Simaii, and the Rabbi allowed their widows to re-marry on the
testimony of women. Even the testimony of a hundred women is only equal
to the evidence of one man (and that only in a case like the foregoing;
it is inadmissible in any other matter).
_Yevamoth_, fol. 115, col. 1.
"Whosoever is not instructed in Scripture, in the Mishna, and in good
manners," says Rabbi Yochanan, "is not qualified to act as a witness."
"He who eats in the street," say the Rabbis, "is like a dog;" and some
add that such a one is ineligible as a witness, and Rav Iddi bar Avin
says the Halachah is as "some say."
_Kiddushin_, fol. 40, col. 2.
Even when a witness is paid, his testimony is not thereby invalidated.
_Kiddushin_, fol. 58, col. 2.
Testimony that is invalidated in part is invalidated entirely.
_Bava Kama_, fol, 73, col. 1.
Let witnesses know with whom and before whom they bear testimony, and
who will one day call them to account; for it is said (Deut. xix. 17),
"Both the men between whom the controversy is shall stand before the
Lord."
_Sanhedrin_, fol. 6, col. 2.
Those that eat another thing (i.e., not pork, but those who receive
charity from a Gentile.--Rashi and Tosefoth) are disqualified from being
witnesses. When is this the case? When done publicly; but if in secret,
not so.
Ibid., fol. 26, col. 2.
He who swears falsely in a capital case is unreliable as a witness in
any other suit at law; but if he has perjured himself in a civil case
only, his evidence may be relied upon in cases where life and death are
concerned.
Ibid., fol. 27, col. 1.
He who disavows a loan is fit to be a witness; but he who disowns a
deposit in trust is unfit.
_Shevuoth_, fol. 40, col. 2.
Shimon ben Shetach says, "Fully examine the witnesses; be careful with
thy words, lest from them they learn to lie."
_Avoth_, chap. 1.