"
Lawful" and "
legal" differ in that "lawful" means to conform to the substance of law, whereas "legal" means to be in conformity with the form of law. "
A lawful act" is an act allowed by law. "
A legal act" is any act that is technically in accordance with the forms and usages of law. In this regard, "
illegal" and "
invalid" are very close in the sense. So, a contract, if it is executed without the required formalities, can be regarded as "
invalid" or "
illegal", but it does not necessarily mean the contract is unlawful. (EX) In Japan, marriage under 16 is lawful but subject to various legal requirements.
"
Lawful" more clearly suggests an ethical content than does "
legal". "
Legal" merely denotes compliance with technical or formal rules, whereas "
lawful" usually means a moral substance and/or ethical permissibility. An additional distinction is that "
legal" is used as the synonym of "
constructive", while lawful is not. "
Legal fraud" is "
fraud implied by law", or "
made out by construction", but "
lawful fraud" would be a contradiction in terms. "
Legal" is also used as the antithesis of "
equitable", "
just". As a result, "
legal estate" is the correct usage, instead of "
lawful estate". Under certain circumstances, however, the two words are used as exact equivalents. "
A lawful writ", "
a lawful warrant", or "
a lawful process" is the same as "
a legal writ", "
a legal warrant", or "
a legal process"
paco.