Luther held strenuously the view that marriage was a purely external contract for the purpose of sexual satisfaction, and in no way entered into the spiritual life of the man.

On this ground he sees no objection in the so-called mixed marriages, which were, of course, frowned upon by the Catholic Church.

In his sermon on "Married Life" he says: "Know therefore that marriage is an outward thing, like any other worldly business.

Just as I may eat, drink, sleep, walk, ride, buy, speak, and bargain with a heathen, a Jew, a Turk, or a heretic, so may I also be and remain married to such an one, and I care not one jot for the fool's laws which forbid it....

A heathen is just as much man or woman, well and shapely made by God, as St.Peter, St.Paul, or St.Lucia." Nor did he shrink from applying his views to particular cases, as is instanced by his correspondence with Philip von Hessen, whose constitution appears to have required more than one wife.