The natural order, charity, justice, and related principles give every child the right to be born with bodily health, if such an event is possible. If it is not possible in particular circumstances, then _melius esse quam non esse_, and the decision in each case depends on its own qualities. If a physician knows that a person who has been infected with syphilis is about to marry, should the physician warn the innocent party? There are several conditions: (1) the infected person about to marry may be actively infectious; (2) the person may be probably infective, as any one is who has once had syphilis; (3) the physician may know the fact of the infection officially or unofficially; (4) the infective person may have gone to the physician for treatment for a condition not connected with the syphilis--say, for a bronchitis or a broken bone--and the physician in the examination discovers syphilis. Again, there are various kinds of secrets. St. Alphonsus Liguori[161] classifies secrets in three groups: (1) natural; (2) promised; (3) entrusted secrets. A natural secret is one which obliges us in justice to observe it if divulging it will gravely injure any one in reputation or possessions. We are not obliged to observe a secret of this kind at the risk of our lives unless the damage from the divulging would affect the community gravely. A promised secret obliges to silence either gravely or lightly, according to the intention of the promiser. Where reasonable doubt exists as to grave obligation, such obligation does not exist. A promise to secrecy made even under oath is not binding if one is obliged in justice to reveal the secret; therefore we must testify to the crime of another when a judge legitimately demands our testimony, even if we have promised not to tell anything. If a secret is entrusted to one, and divulging would cause grave damage, but justice, or similar circumstances, do not oblige us to reveal it, we are bound to observe it even when questioned by legitimate authority. Then we may answer we know nothing about it, at least for revelation. St. Alphonsus's text is: "Potes respondere te nihil scire, scilicet ad revelandum." His meaning seems to be: "You may say you know nothing about the matter inquired into." Any other signification would be futile. To say literally, "I do not know anything I may tell," would only expose one to punishment for contempt. He seems to make the answer a conventional denial, like the "not guilty" of a criminal. A judge may not abrogate the natural right by which an entrusted secret is protected, unless the secret is already known in some other way, or there is a just cause for revealing it.[162] [161] _Theologia Moralis_, iv, n. 970 et seq. [162] Cf. De Lugo, _De Justitia et Jure_, disp. 14, n. 141.