The opinion of the lawyers, and the discretion of the magistrates, had introduced, in the time of Tacitus, some legal restraints, which might support his contrast of the boni mores of the Germans to the bonae leges alibi — that is to say, at Rome (de Moribus Germanorum, c. 19.). Tertullian (ad Nationes, l. i. c. 15) refutes his own charges, and those of his brethren, against the heathen jurisprudence.