" The thrust of his parent's views, at least when applied to the situation of Mileva Maric rather than Marie Winteler, was that a wife was a luxury, affordable only when a man was making a comfortable living. "I have a low opinion of that view of a relationship between a man and wife," he [Einstein] told Maric, "Because it makes the wife and the prostitute distinguishable only insofar as the former is able to secure a life-long contract. "

― Walter Isaacson , Einstein: The Life of a Genius