Oaths Law and Legal Definition
An oath is a declaration made according to law, before a competent tribunal or officer, to tell the truth; or it is the act of one who, when lawfully required to tell the truth, takes God to witness that what he says is true. Generally, oaths are personal promises to uphold one's duty, such as a duty to be loyal, honest, etc. Oaths may classified as promissory, assertory, judicial or extra judicial.
Promissory oaths include those taken by public officers on entering into office, to support the constitution of the United States, and to perform the duties of the office.
Assertory oaths are required by law, not in judicial proceedings, nor from officers entering into office, when the party merely asserts the fact to be true.
Judicial oaths are those administered in judicial proceedings.
Extra-judicial oaths are those taken without authority of law, which, though binding, are not punishable by perjury if false.