The Philosophy of Law: Private Right, § 26: Monogamy and Equality in Marriage
For the same reasons, the relation of the Married Persons to each other is a relation of EQUALITY as regards the mutual possession of their Persons, as well as of their Goods. Consequently Marriage is only truly realized in MONOGAMY; for in the relation of Polygamy the Person who is given away on the one side, gains only a part of the one to whom that Personis given up, and therefore becomes a mere res. But in respect of their Goods, they have severally the Right to renounce the use of any part of them, although only by a special Contract.
From the Principle thus stated, it also follows that Concubinage is as little capable of being brought under a Contract of Right, as the hiring of a person on any one occasion, in the way of a pactum forni-cationis. For, as regards such a Contract as this latter relation would imply, it must be admitted by all that any one who might enter into it could not be legally held to the fulfilment of their promise if they wished to resile from it. And as regards the former, a Contract of Concubinage would also fall as a padum tiLrpe; because as a Contract of the hire (locatio, condudio), of a part for the use of another, on account of the inseparable unity of the members of a Person, any one entering into such a Contract would be actually surrendering as a res to the arbi trary Will of another. Hence any party may annul a Contract like this if entered into with any other, at any time and at pleasure; and that other would have no ground, in the circumstances, to complain of a lesion of his Right. The same holds likewise of a morganatic or ‘left-hand’ Marriage contracted in order to turn the inequality in the social status of the two parties to advantage in the way of establishing the social supremacy of the one over the other; for, in fact, such a relation is not really different from Concubinage, according to the principles of Natural Right, and therefore does not constitute a real Marriage. Hence the question may be raised as to whether it is not contrary to the Equality of married Persons when the Law says in any way of the Husband in relation to the Wife, ‘he shall be thy master,’ so that he is represented as the one who commands, and she as the one who obeys. This, however, cannot be regarded as contrary to the natural Equality of a human pair, if such legal Supremacy is based only upon the natural superiority of the faculties of the Husband compared with the Wife, in the effectuation of the common interest of the household; and if the Right to command, is based merely upon this fact. For this Right may thus be deduced from the very duty of Unity and Equality in relation to the End involved.