The basis of something.
A stone laid during the construction of a (usually important) building, the laying of which is usually marked by a ceremony.
A fundamental element; a basic principle.
An axiom.
Something assumed without proof as being self-evident or generally accepted, especially when used as a basis for an argument. Sometimes distinguished from axioms as being relevant to a particular science or context, rather than universally true, and following from other axioms rather than being an absolute assumption.
A requirement; a prerequisite.
Postulated.
To appoint or request one's appointment to an ecclesiastical office.
To assume as a truthful or accurate premise or axiom, especially as a basis of an argument.