462. Fulfillment of Law.--With reference to the manner of fulfilling a law there are a number of questions to be considered: (a) as to the external acts, whether or not one can fulfill the law for another, whether or not the omission of some slight detail renders compliance insufficient, whether or not he who cannot fulfill the whole law is bound to fulfill a part of it, whether or not several obligations can be satisfied at the same time or by the same act, etc.; (b) as to the internal acts, whether or not one must have the intention of meeting the wishes of the lawgiver, whether or not one must be in the state of grace, etc. 463. Personal fulfillment is not always necessary; for an affirmative law requires either that some thing be given, or that some personal act be performed. (a) When the law requires that some thing be given (e.g., that taxes be paid), the obligation can be satisfied through another, since a thing can be transferred from one person to another, who agrees at least interpretatively; (b) when the law requires that a personal act be performed (e.g., that Mass be heard on Sunday), the obligation cannot be satisfied through another, for actions cannot be transferred from one to another. 464. Minute fulfillment is not always necessary; for sometimes the minor details of the fulfillment of a law are expressly prescribed, sometimes they are not. (a) If these details are required by the law itself or by the nature of the case, the law is not satisfied if they are neglected. Example: Friday abstinence ends exactly at midnight, and hence to eat meat even one minute before midnight is to break that abstinence. (b) If the law does not prescribe minute details, these are not required for the fulfillment of the obligation; for laws should not be unduly burdensome. Example: One who is a few minutes late for Mass does not miss Mass, if he is present for the essential parts of the Mass. 465. Partial fulfillment is required of him who cannot make complete fulfillment, only when the part is commanded for its own sake; for that which is commanded by a law is considered by the lawgiver as either an indivisible unit, or as a whole composed of parts that have singly an independent moral value and obligation. (a) If the thing commanded is morally an indivisible unit (e.g., a pilgrimage to a shrine), he who is not able to fulfill the whole law is bound to nothing. Example: One who has made a vow to go on pilgrimage to a distant sanctuary, is not bound to go part of the way, if he is unable to make the entire journey.