John Locke. Treatise on Government. Chapter 6. Of Paternal Power. Section 76.
Thus the natural fathers of families, by an insensible change, became the politic monarchs of them too: and as they chanced to live long, and leave able and worthy heirs, for several successions, or otherwise; so they laid the foundations of hereditary, or elective kingdoms, under several constitutions and mannors, according as chance, contrivance, or occasions happened to mould them. But if princes have their titles in their fathers right, and it be a sufficient proof of the natural right of fathers to political authority, because they commonly were those in whose hands we find, de facto, the exercise of government: I say, if this argument be good, it will as strongly prove, that all princes, nay princes only, ought to be priests, since it is as certain, that in the beginning, the father of the family was priest, as that he was ruler in his own houshold.