(c) If no serious reasons can be found to prove or directly disprove that a certain law has ceased or been abrogated, the principle to be followed is: “In doubt decide for that which has the presumption.” In this case the presumption is for the continuance of the law, since it was certainly made, and there is no probability for its non-continuance. Example: Sempronius learns that certain mitigations have been made in the law of fasting, and wonders whether the same is true as regards the law of abstinence; but he has no reason to think that any change has been made on this latter point. 661. In the above cases negative doubt was solved generally in favor of non-obligation as against obligation. But there are two cases in which negative doubt must be settled in favor of obligation, according to the rule: “In doubt follow that which is safer.” The two cases are: (a) Negative doubt must be settled in favor of obligation, when the doubt is about a matter of such importance that it does not permit the taking of risks in its performance, as when there is question of laws that safeguard the supreme rights of man, or of laws that prescribe the essentials to be used in the administration of the Sacraments. Example: Sempronius adopts a newly-born infant abandoned at his door. As there is nothing to indicate whether the baby has been baptized or not, Sempronius takes the safer course and has it baptized. (b) Negative doubt must be settled in favor of obligation when it persists because no reflex principle is found, or none that seems to be suitable for the case. Example: Titus wavers between uncertainties about the existence of a law; he can discover no reasons pro or con, and he knows no principle or presumption to guide himself by in his difficulty. He does not know or even think that he may act as if the law were non-existent, and hence he must inquire further, or else act as if the law did exist. 662. Opinion.--The duty of one whose state of mind is opinion is as follows: (a) If he is able to remove every objection against his judgment or to make unimportant such objection or objections as remain, his opinion has become moral certainty (see above, 644 Sqq.), and he may follow it as a safe guide. Example: Caius promises to marry Sempronia, but his parents forbid the marriage. Caius opines that he should keep his promise, but to be sure he consults his pastor. The latter shows him that the opposition to his marriage is unreasonable, and thus sets at rest the difficulties of Caius. (b) If a person is not able to remove one or more important objections against his judgment, his opinion has not become moral certitude, and he may not follow it as a safe guide. Example: If Caius’ pastor holds that the parents are right and Caius wrong in the question of marriage with Scmpronia, so that Caius, while still thinking he should keep his promise, has serious fears that it would be a wrong step, the young man should not follow his own view.