(b) When the law forbids something, it is possible that one does not will the omission commanded and yet fulfills one’s obligation. Example: He who intends to eat meat on a day of abstinence which he thinks is a meat day, but, being unable to find what he wants, omits the meat, satisfies the law, which requires only that one omit what is forbidden and have no will to violate the law. (c) When the law commands that an act be performed, one must perform the act willingly, since the law being for humans intends that fulfillment be made in a human manner. Examples: He who is dragged to church and forcibly detained there during Mass, does not satisfy the law of sanctifying the Sunday, since force makes his assistance at Mass involuntary (see 52). A child that goes to church only to escape punishment satisfies its duty, if, in spite of reluctance, it really intends to hear Mass, for fear does not necessarily make an act involuntary (see 41 sqq.). 477. As to the intention required in fulfilling a law, it is to be noted that one must have, at least implicitly, the intention of doing what the law prescribes, in the case given in the third section (c) of the preceding paragraph. Example: He who goes to church on Sunday while Mass is being said with no other purpose than that of hearing the music or of waiting for a friend, does not satisfy the Sunday duty, since he does not at all intend to hear Mass. 478. The following kinds of intention, though to be recommended, are not necessary for the fulfillment of a law. (a) It is not necessary, as a rule, that one intend to satisfy one’s obligation, for human lawgivers have not generally the power or the intention to command acts that are purely internal (see 374, 426). Examples: He who hears Mass on a holyday not intending to perform his duty, as he does not know that it is a holyday, has satisfied the law. He who says the rosary out of devotion and then remembers that he has an obligation of saying it because of a promise made or of a penance received, can regard the rosary said as a fulfillment of his obligation. (b) It is not necessary that one intend that which the lawgiver had in mind as the purpose of the law; for “the end of the law is not a part of the law.” Example: A person who takes only one full meal during Lent, observes the letter of the law; but he misses its spirit if he eats or drinks greedily, daintily or copiously, in order to avoid the mortification intended by the law. 479. If one intends to perform what a law prescribes, but at the same time expressly intends not to satisfy, by that performance, the obligation imposed, one’s act is sufficient or insufficient for fulfillment according to the source from which the obligation arises.