(b) An irritant law should be regarded as not obligatory _ipso facto_, when the end of the law does not clearly demand obligation before judicial declaration; for, as remarked above, the invalidation of an act is something odious, and hence not to be taken for granted. Thus, laws that void an act, contract or instrument on account of lack of some legal form, do not affect the natural rights or obligations before sentence. 560. Though the civil lawgiver has the right to annul certain acts, and thus to extinguish moral rights or obligations that would otherwise exist, laws seemingly irritant frequently have a different intention. (a) Laws that make a claim unenforceable in court do not destroy the natural right of the claimant. Example: The Statute of Limitations in modern states generally bars the right to pursue a debtor in court after six years; nevertheless, the moral obligation of the debtor remains. (b) Laws that make an act or contract voidable do not nullify, but only grant to the person concerned the right to attack validity before the courts. Hence, if the conditions for valid contract required by natural law are present (knowledge, consent, etc.), moral rights and obligations are not voided. Example: Under the civil law some contracts made by minors may be retracted by them. But, as long as such a contract is not disavowed, the other party has a moral right to insist on its execution; if it has been ratified after majority, the former minor has no moral right to seek the benefit of the law by asking for rescindment. 561. With reference to penalty, four kinds of laws can be distinguished. (a) Purely preceptive laws are such as oblige under pain of sin, but not under pain of punishment. There are church laws of this kind (such as the command to assist at Mass on Sunday), and there are also some civil laws that do not oblige under penalty (e.g., statutes governing the age for legal marriage, for, if a couple misrepresented their age, they might be prosecuted for the misrepresentation, but not for the act of marriage). (b) Purely penal laws are such as oblige under pain of juridical fault and punishment, but not under pain of sin (e.g., a law that punishes negligence in driving as defined by itself, even though there be no moral culpability involved). (c) Mixed laws disjunctively are such as oblige under sin either to obey the law or to suffer the penalty (e.g., a law that commands one either to get a license before fishing or hunting, or to pay a fine if caught doing these things without a license). (d) Mixed laws conjunctively are such as oblige under pain of both sin and punishment (e.g., the laws that forbid injustice and command the punishment of transgressors).