During the 1950s, Summerskill wrote a series of letters to her daughter Shirley, who, like her mother, was an active feminist. Shirley studied medicine in Oxford at that time and later became a doctor and a Member of Parliament and of Cabinet. Edith Summerskill's letters to Shirley were collected and published in a book "Letters to My Daughter" (1957). Summerskill outlines her belief that women are superior to men in almost every way. In support of such a theory Summerskill presents three "facts": firstly, that only women can enjoy two worlds of creative enterprise, the biological and the intellectual. Secondly, she suggests women are physically stronger, live longer are constitutionally tougher, having greater stamina. Finally, she believes women have equal if not greater intellect than men.