Catholic Encyclopedia (1913)/Good Faith
A phrase employed to designate the mental and moral state of honest, even if objectively unfounded, conviction as to the truth or falsehood of a proposition or body of opinion, or as to the rectitude or depravity of a line of conduct. One who is in this condition, so far as the violation of positive law, or even, in certain junctures, of the natural law, is concerned, is said to labour under an invincible error, and hence to be guiltless. This consideration is often invoked in behalf of those who are outside of the visible affiliation of the Catholic Church. It is not unfrequently applied to determine the degree of right or obligation prevailing in the various forms of human engagements, such as contracts, etc. In the matter of prescription it is held to be an indispensable requirement whether there be question of acquiring dominion or freeing oneself from a burden. Likewise, in deciding the duty incombent upon one who finds himself in possession of another's property, cognizance is taken of the good faith with which perchance the holding has been begun and accompanied. Finally, if a person, although in the actually in state of mortal sin, were in good faith to come to Holy Communion, such a one, according to the judgement of many theologians, would receive sanctifying grace. The reason alleged by them, although not regarded by other moralists as convincing, is that good faith saves the communicant from the conscious interposition of any obstacle to the productive activity of the Sacrament.
JOSEPH F. DELANY