Bona Fides, a Latin expression signifying good faith, enters as a legal doctrine largely into the consideration of matters of agreement, contract, damage, trusts, and other departments of the law; and in all of them it requires the absence of fraud, or unfair dealing. This term, however, does not appear to occupy any formal or technical place in the law of England. It is the foundation of many just and enlightened maxims in the Roman jurisprudence, which in this respect, as in many others, has been followed by the legal system of Scotland. In the law of that country, a person who possesses and enjoys property upon a title which he honestly believes to be good, although it may be bad, is protected against the consequences of this illegal position, and he is entitled to retain the fruits or profits which he has reaped or received during his bona-fide occupancy. But this protection ends when the possessor becomes aware of the insufficiency of his title, whether by private knowledge or otherwise. This rule, which is largely founded on the negligence of the true owner, would extend to a claim for interest on money erroneously paid to a person honestly believing himself the creditor. In the Scots law, again, while honest belief will not render valid a second marriage, the first subsisting, it would, it is thought, have the effect of rendering the children of such second or putative marriage legitimate, and would even confer rights of succession on the innocent husband or wife. The law of England is not so indulgent, for there children born under such circumstances would certainly be deemed bastards. As a general rule, parties are supposed to contract at arm's length, and therefore there is not much room for the doctrine of bona fides in considering business agreements, which depend on the true construction of the documents exchanged. Positive misrepresentation or fraud will of course upset a contract if it led to error, but it is only in certain classes of contracts, such as partnership, suretyship, insurance, &c., that the plea of undue concealment has much force. The amount of damages recovered is sometimes affected by the good or bad faith of the wrongdoer, as in the case of wilful trespass of mining boundaries, where the nature of the subject renders a severe check necessary. In trust administration the beneficiaries are entitled to place much confidence in the trustees, and bad faith on their part is severely dealt with. See BASTARDS, BASTARDY; and see on the subject of this article generally, CONTRACT, DAMAGE, EXECUTOR, GUARDIAN, MARRIAGE, TRUSTEE.
The interpretation of the term Bona-fide Traveller has given no little trouble to the magistrates of Scotland in reference to the famous 'Forbes Mackenzie Act' (q.v.).