Sir John W. Salmond, Jurisprudence (1913)
“ It is requisite that the law should postulate one or more first causes, whose operation is ultimate, and whose authority is underived. In other words there must be found in every legal system certain ultimate principles, from which all others are derived, but which are themselves self-existent. Before there can be any talk of legal sources, there must be already in existence some law which establishes them and gives them their authority. ”
