Regarding Roger Scruton’s quarrel with Paul Griffiths about the relation of marriage to the state, Lord Stowells analysis in Dalrymple v Dalrymple seems very apposite:
Marriage in its origin is a contract of natural law; it may exist between two individuals of different sexes although no third person existed in the world, as happened in the case of the common ancestors of mankind. It is the parent not the child of civil society. In civil society, it becomes a civil contract regulated and prescribed by law and endowed with civil consequences. In most civilized countries, acting under a sense of the force of sacred obligations, it has had the sanctions of religion superadded; it then becomes a religious, as well a natural and civil, contract; for it is a great mistake to suppose that because it is the one, therefore it may not likewise be the other. Heaven itself is made a party to the contract and the consent of the individuals pledged to each other is ratified and consecrated by a vow to God.