(b) In criminal cases the prosecution is unjust if the accused is clearly innocent. But the defense is not unjust, even though the accused is known to be guilty, for both natural and positive law give the accused a right of defense, and hence he may choose or may be given an advocate, in spite of his guilt.

2001. Duty of a Lawyer When the Justice of a Cause Is Doubtful.—(a) In a civil cause, the lawyer may act, whether for the plaintiff or for the defendant. He may even take a case whose justice seems less probable, for the purpose of the trial is to settle the doubt, and not infrequently the cause that seemed doubtful or less probable at the outset is vindicated by the examination. Some moralists distinguish for cases in which the doubt is one of fact between the defendant and the plaintiff: if the former’s case is less or equally probable, they say, one may take it, but not so if this is true of the latter’s case.

(b) In a criminal case, when life, reputation or other grave issue is involved, the common opinion is that a lawyer may not prosecute if the case of the people is doubtful or less probable, but he may defend, as was just said, even though he is certain that the accused is guilty. The office of the prosecutor is not necessarily to secure a conviction, but to see that justice is upheld, while the office of the defender is to take care that an accused person is deprived of no right or protection that he should have under the law.

2002. If a lawyer through ignorance takes an unjust case, thinking it just, he is excused or not excused according to the character of his ignorance (see 28, 249). (a) Thus, antecedent ignorance excuses from sin and restitution; (b) concomitant ignorance excuses from restitution, but not from sin; (e) consequent ignorance excuses from neither sin nor restitution, if it is crass or affected, but it diminishes responsibility, if it is only slightly sinful.

2003. Duty of a Lawyer Who Discovers that a Case Is Really Unjust.—(a) A lawyer who took a case in the belief that it was just, but discovers that it is really unjust, owes it to himself to abandon the case, for he cannot honorably cooperate with iniquity. The same principle applies, if a client insists upon unjust courses in the support of his case, even though the cause itself be just.

(b) The lawyer owes it to his client in the hypothesis we are considering to preserve the latter’s confidence inviolate (see 1988). He should endeavor to persuade the client to abandon the case; but since the client’s case is unjust, he may not recommend a compromise, except perhaps in reference to expenses.

2004. Lawyer’s Duties towards Client.—Since every contract depends on the mutual consent of the contractants, and since the purpose of the person who retains a lawyer is to receive honest advice and assistance and to give in return a fair compensation, it follows that the lawyer’s duty to a client is to give what is thus expected and not to exact more than this deserves.

(a) Before the case the lawyer should be perfectly candid with the client as to the advisability of litigation or of the employment of himself as counsel in the case. If there is a reason why he would be a less desirable advocate in the case, he should speak of this, so that his consultant may have freedom of choice. He should also study the question presented to him, and give his honest opinion on the strength of the case. If a fair and amicable adjustment outside of court can be made, the lawyer should recommend that this be done, and if it is not clear which party is right, he should advise a compromise.

(b) During the case the lawyer should be faithful to the interests of his client and diligent in the affairs for which he is engaged. Loyalty demands that the advocate give his undivided devotion to his client (e.g., he may not give assistance to the adverse party, he may not receive gifts or compensations from that party; see Code, Canons 1666, 2407), and that he respect the client’s confidences (e.g., he may not use to the client’s disadvantage the information given him). Diligence requires that the lawyer use his best ability and efforts to the end that the client, no matter how poor or unpopular or persecuted, may receive all the remedies or defenses that the law grants him, and that his case may be terminated with all possible speed.

(c) After the case he should be honest in his charges and true to the confidence that was reposed in him. The compensation for the lawyer’s services should be just, that is, a fair return for what he gave. The amount of the fee should be fixed, therefore, by such standards as the law or custom, or by the value of that which the lawyer devotes to the case (e.g., his time and labor, his loss of other employment or prospects, the risk he takes in undertaking the case), or of that which the client receives (e.g., the amount which he gains, the benefit he receives). The wealth of a client does not justify an excessive charge, but the poverty of the client makes it a duty of charity at times to lessen the charges or to make no charges at all (see 1236-1239). It is clear that a lawyer should not compensate himself from the client’s business contrary to the latter’s just wishes.