An example will illustrate this better than anything else.  Take a physician or lawyer, the custodian of a professional secret, or a priest with knowledge safeguarded by the seal of the confessional.  These men either may not or should not reveal to others unconcerned in the matter the knowledge they, possess.  There is no one but should be aware of this, but should know that when they are questioned, they will answer as laymen, and not as professionals.  They will answer according to outside information, yes or no, whether on not such conclusion agree with the facts they obtained under promise of secrecy.  They simply put out of their mind as unserviceable all professional knowledge, and respond as a man to a man.  Their standing as professional men puts every questioner on his guard and admonishes him that no private information need be expected, that he must take the answer given as the conclusion of outside evidence, then if he is deceived he has no one to blame but himself, since he was warned and took no heed of the warning.

Again we repeat, the margin between mental restriction and falsehood is a safe, but narrow one, the least bungling may merge one into the other.  It requires tact and judgment to know when it is permissible to have recourse to this artifice and how to practise it safely.  It is not a thing to be trifled with.  In only rare circumstances can it be employed, and only few persons have the right to employ it.

CHAPTER XCIV.  RESTITUTION.

A peculiar feature attaches to the sins we have recently treated, against the Fifth, Sixth, Seventh, and Eighth commandments.  These offenses differ from others in that they involve an injury, an injustice to our fellow-man.  Now, the condition of pardon for sin is contrition; this contrition contains essentially a firm purpose that looks to the future, and removes in a measure, the liability to fall again.  But with the sins here in question that firm purpose not only looks forward, but backward as well, not only guarantees against future ill-doing, but also repairs the wrong criminally effected in the past.  This is called restitution, the undoing of wrong suffered by our neighbor through our own fault.  The firm purpose to make restitution is just as essential to contrition as the firm purpose to sin no more; in fact, the former is only a form of the latter.  It means that we will not sin any more by prolonging a culpable injustice.  And the person who overlooks this feature when he seeks pardon has a moral constitution and make-up that is sadly in need of repairs; and of such persons there are not a few.