A witness who will not come of himself may be summoned, and if he fail in appearing, he shall be liable for any harm which may ensue:  if he swears that he does not know, he may leave the court.  A judge who is called upon as a witness must not vote.  A free woman, if she is over forty, may bear witness and plead, and, if she have no husband, she may also bring an action.  A slave, male or female, and a child may witness and plead only in case of murder, but they must give sureties that they will appear at the trial, if they should be charged with false witness.  Such charges must be made pending the trial, and the accusations shall be sealed by both parties and kept by the magistrates until the trial for perjury comes off.  If a man is twice convicted of perjury, he is not to be required, if three times, he is not to be allowed to bear witness, or, if he persists in bearing witness, is to be punished with death.  When more than half the evidence is proved to be false there must be a new trial.

The best and noblest things in human life are liable to be defiled and perverted.  Is not justice the civilizer of mankind?  And yet upon the noble profession of the advocate has come an evil name.  For he is said to make the worse appear the better cause, and only requires money in return for his services.  Such an art will be forbidden by the legislator, and if existing among us will be requested to depart to another city.  To the disobedient let the voice of the law be heard saying:—­He who tries to pervert justice in the minds of the judges, or to increase litigation, shall be brought before the supreme court.  If he does so from contentiousness, let him be silenced for a time, and, if he offend again, put to death.  If he have acted from a love of gain, let him be sent out of the country if he be a foreigner, or if he be a citizen let him be put to death.

Book xii.  If a false message be taken to or brought from other states, whether friendly or hostile, by ambassadors or heralds, they shall be indicted for having dishonoured their sacred office, and, if convicted, shall suffer a penalty.—­Stealing is mean; robbery is shameless.  Let no man deceive himself by the supposed example of the Gods, for no God or son of a God ever really practised either force or fraud.  On this point the legislator is better informed than all the poets put together.  He who listens to him shall be for ever happy, but he who will not listen shall have the following law directed against him:—­He who steals much, or he who steals little of the public property is deserving of the same penalty; for they are both impelled by the same evil motive.  When the law punishes one man more lightly than another, this is done under the idea, not that he is less guilty, but that he is more curable.  Now a thief who is a foreigner or slave may be curable; but the thief who is a citizen, and has had the advantages of education, should be put to death, for he is incurable.