The seventh letter shows how the Jesuits accommodated the fifth commandment to an age of brawling and duelling. It is quite lawful to fight a duel if a man would otherwise incur dishonour (Escobar); it is lawful to pray to God to kill a menacing enemy (Hurtado); it is lawful to kill a culumniator and his false witnesses (Molina); it is lawful to pursue and kill a man who has dealt you a blow--provided you have merely a technical regard for your honour, and do not feel vindictive (Escobar); it is lawful to kill a contumelious man, if that is the only way to arrest the injury (Lessius); it is lawful, if necessary, to kill an intending thief even if he attempt to take only a single gold coin (Molina); and--a very significant doctrine--it is lawful for a monk to kill a man who defames his monastery or his order, if there is no other way to arrest the defamation (Amico). These were fine doctrines for the age of Louis XIV. The eighth letter quotes distinguished theologians who permit a judge to accept secret and illegal presents, provided they are given out of gratitude, or merely to encourage him in giving honest verdicts (Molina); and others who teach that, while usury (which then meant any interest in money) is forbidden, the lender of money may exact a certain additional sum in the name of gratitude (Escobar, etc.); that a bankrupt may keep back sufficient property to enable himself and his family to live "decently" (Escobar); that money earned by crime or vice has not to be restored (Lessius, etc.); and that "a prostitute, virgin, married woman, or nun" is strictly entitled to the money promised her for vice (Filliutius). The ninth letter shows how gluttony is condoned, and scourges the familiar casuistic doctrine of mental reservation. In the tenth letter we learn that a frail woman may receive into her house her partner in sin if she "cannot decently refuse."