For my module about Feminist Philosophy I talked about an article by Patricia Hill Collins, 'Shifting the Center: Race, class and feminist theorizing about motherhood (1994). It is a beautifully written paper in which Collins, an African-American Feminist Scholar, describes the agonies involved in mothering children within a society which treats their ethnicity as inferior. I introduced the paper as a way to convey the force of what's known as the 'commonality problem' in defining the class 'women'. Here is the problem.