Affidavit of good faith

What does Affidavit of good faith mean in American Law?

The definition of Affidavit of good faith in the law of the United States, as defined by the lexicographer Arthur Leff in his legal dictionary is:

In various legal situations statutes or court rules require that a party file an affidavit swearing that he is not doing during the proceeding anything he ought not to be doing, e.g., a party seeking to appeal the decision of a lower court may have to file an affidavit that he is not taking his appeal for purposes of delay. Similarly, mortgagors are sometimes required to file an affidavit that they are not giving the mortgage to defeat, defraud, hinder, or delay creditors.

Requiring such affidavits might on the surface seem rather silly, but it is fair to say that many people who would be perfectly willing both to appeal solely for delay, and to give a mortgage in order to harm particular creditors, would not be equally willing solemnly to lie, i.e., to commit perjury about what they were doing. This is especially so since a lawyer is much more explicitly told by the Code of Professional Responsibility to stop his client’s perjury than his dilatory tactics or fraudulent conveyance, and lawyers are usually necessary to these transactions. All of this does not mean that false affidavits are never filed, especially since it does not often take much for a person to convince himself of his own actual good faith. But, even if action is rarely if ever taken against the false affiant, these affidavits of good faith are not without legal utility.