e tribes of people."[44] But this extreme rigor as to
competency, rejected by our law, is not found to extend to the _genus_
of evidence, but only to a particular _species_,--personal witnesses.
Indeed, after all their efforts to fix these things by positive and
inflexible maxims, the best Roman lawyers, in their best ages, were
obliged to confess that every case of evidence rather formed its own
rule than that any rule could be adapted to every case. The best
opinions, however, seem to have reduced the admissibility of witnesses
to a few heads. "For if," said Callistratus, in a passage preserved to
us in the Digest, "the testimony is free from suspicion, either on
account of the quality of the _person_, namely, that he is in a
reputable situation, or for _cause_, that is to say, that the testimony
given is not for reward nor favor nor for enmity, such a witness is
admissible." This first description goes to _competence_, between which
and _credit_ Lord Hardwicke justly says the discrimination is very nice.
The other part of the text shows their anxiety to reduce credibility
itself to a fixed rule. It proceeds, therefore,--"His Sacred Majesty,
Hadrian, issued a rescript to Vivius Varus, Lieutenant of Cilicia, to
this effect, that he who sits in judgment is the most capable of
determining what credit is to be given to witnesses." The words of the
letter of rescript are as follow:--"You ought best to know what credit
is to be given to witnesses,--who, and of what dignity, and of what
estimation they are,--whether they seem to deliver their evidence with
simplicity and candor, whether they seem to bring a formed and
premeditated discourse, or whether on the spot they give probable matter
in answer to the questions that are put to them." And there remains a
rescript of the same prince to Valerius Verus, on the bringing out the
credit of witnesses. This appears to go more to the _general_ principles
of evidence. It is in these words:--"What evidence, and in what measure
or degree, shall amount to proof in each case can be defined in no
manner whatsoever that is sufficiently certain. For, though not always,
yet frequently, the truth of the affair may appear without any matter of
public record. In some cases the number of the witnesses, in others
their dignity and authority, is to be weighed; in others, concurring
public fame tends to confirm the credit of the evidence in question.
This alone I am able, and in a few words, to gi