From Charles Loyseau's Treatise of Orders and Plain Dignities (7.92):
This is certainly very conducive to the extreme respect and reverence in which the people of France, more than all others, holds its kings and their blood. In the excellence of that blood no blemish nor corruption ought to be imagined. On the contrary, this royal blood purifies and ennobles all other blood with which it is mingled. For it must be acknowledged to be of much more noble and august material and quality than that of other men. Plato said that by comparison with other men those who are born to command are made of another metal. More to the point, Aristotle said that kings are of a mean genus between God and the people.