esses might
not easily depart from the truth, the Law commanded that they should
be most carefully examined, and that those who were found untruthful
should be severely punished, as stated in Deut. 19:16, seqq.

There was, however, a reason for fixing on this particular number, in
token of the unerring truth of the Divine Persons, Who are sometimes
mentioned as two, because the Holy Ghost is the bond of the other two
Persons; and sometimes as three: as Augustine observes on John 8:17:
"In your law it is written that the testimony of two men is true."

Reply Obj. 9: A severe punishment is inflicted not only on account of
the gravity of a fault, but also for other reasons. First, on account
of the greatness of the sin, because a greater sin, other things
being equal, deserves a greater punishment. Secondly, on account of a
habitual sin, since men are not easily cured of habitual sin except
by severe punishments. Thirdly, on account of a great desire for or a
great pleasure in the sin: for men are not easily deterred from such
sins unless they be severely punished. Fourthly, on account of the
facility of committing a sin and of concealing it: for such like
sins, when discovered, should be more severely punished in order to
deter others from committing them.

Again, with regard to the greatness of a sin, four degrees may be
observed, even in respect of one single deed. The first is when a sin
is committed unwillingly; because then, if the sin be altogether
involuntary, man is altogether excused from punishment; for it is
written (Deut. 22:25, seqq.) that a damsel who suffers violence in a
field is not guilty of death, because "she cried, and there was no
man to help her." But if a man sinned in any way voluntarily, and yet
through weakness, as for instance when a man sins from passion, the
sin is diminished: and the punishment, according to true judgment,
should be diminished also; unless perchance the common weal requires
that the sin be severely punished in order to deter others from
committing such sins, as stated above. The second degree is when a
man sins through ignorance: and then he was held to be guilty to a
certain extent, on account of his negligence in acquiring knowledge:
yet he was not punished by the judges but expiated his sin by
sacrifices. Hence it is written (Lev. 4:2): "The soul that sinneth
through ignorance," etc. This is, however, to be taken as applying to
ignorance of fact; and not to ignorance o