(a) Thus, according to their relative dignity and jurisdiction there are higher and lower courts, courts of the first, second and last instance.
(b) According to the cases they try, courts are either civil (in which redress of private injuries is sought) or criminal (in which the community prosecutes public wrongs).
(c) According to the law which they use courts are ecclesiastical or secular.
(d) According to the form of procedure used and the remedies applied, courts in the United States are divided into courts of common law, courts of equity, probate, admiralty, and military courts.
1942. Jurisdiction.—Authority is necessary in a judge, for judgment is a binding decision that may be executed by force, and this supposes that he who pronounces the judgment is the superior of the person on whom the judgment is passed, Hence, he who acts as judge when he lacks jurisdiction acts invalidly (unless jurisdiction is supplied, as in common error for an ecclesiastical judge, in Canon 209), and offends against the rights of another judge and of the person on whom he passes sentence. Examples would be secular judges acting in ecclesiastical cases or ecclesiastical judges acting in temporal cases.
1943. The Qualifications of a Judge.—(a) Mentally, he must be endowed with knowledge of the law and with prudence, so as to be competent to pronounce correctly on the questions that are brought to him for decision; for, as being the authorized interpreter and custodian of the law, he is bound by quasi-contract with the community and with those who appear before him to be competent for these offices. If a judge realizes that he is incompetent in these ways, he must either resign his office, or make up for his deficiency by study or consultation with those who are more learned than himself. A juryman, being a layman to the law, is not expected to have the mental equipment of a lawyer; but it is his duty to give his attention to the statements, arguments and testimony and to the instructions of the judge.
(b) Morally, the judge must be a lover of justice, whether commutative, distributive or legal; for the proper office of the judge is to apply the law to particular cases and to declare officially the mutual rights and obligations of litigants who are before him. He must not be a respecter of persons, one who is moved for or against a man on account of rank, position or wealth, nor one who is swayed by fear or favor, by popular outcry or personal ambition. Not only legal but also commutative justice obliges him to perform his duties conscientiously; for in taking his office he enters into a quasi-contract with the community to execute his functions faithfully and well, and similarly by trying a case he engages that those before him will receive evenhanded justice. A juror should be a conscientious person who is openminded and free from prejudice for or against those on whom he has to vote.
1944. Conduct of a Judge.—A judge must be above suspicion, since respect for the courts is the very life of the State. But there is good reason to suspect a judge who judges in his own case, or in a case in which he will be naturally inclined to favor one side. Hence the duty of abstaining from certain things.
(a) Thus, he should avoid business, social and political activities that will give ground for belief that he uses his office for the promotion of private interests.
(b) He should not act in a case in which his own advantage or the advantage of his friends might appear to conflict with the duty of strict impartiality, as when he has personal litigation in the court, or when a near relative of his is party in a controversy, or when one of the contestants is his personal or political friend or enemy, etc. Canon 1613 of the Code forbids a church judge to act in the case of a person related by blood or marriage in the direct line or in the first and second degrees of the collateral line, or of a person for whom he is guardian or administrator, or in cases in which he had previously acted as advocate or proxy, or from which he stands to profit or lose.