Original sentence: Mansfield then offers an analysis of the historical forces in the nineteenth and early twentieth centuries, singling out Simone de Beauvoir, Betty Friedan, and Germaine Greer as the key writers to have influenced, what he considers to be, the dismantling of manliness.These writers shared two common hypotheses they derived from earlier writers: from Marx they drew the theory of economic exploitation, and from Nietzsche their flirtations with nihilism
Edited sentence: In Mansfield's view, all these feminists shared two common insights that were derived from earlier philosophers:  from Marx they drew the theory of economic exploitation, and from Nietzsche their flirtations with nihilism.Mansfield then offers an analysis of the historical forces in the nineteenth and early twentieth centuries, singling out Simone de Beauvoir, Betty Friedan, and Germaine Greer as the central villains in what he describes as the dismantling of manliness