Aristotle's moral philosophizing seemed a hopelessly outmoded form of metaphysical speculation from which it was vital to distinguish contemporary philosophic practice. Spencer's formulation of evolutionism and its relation to ethics was attractive to many because it took the sting out of evolutionary theory. Darwinism challenged traditional conceptions of the nature and value of moral theorizing. Sidgwick's Methods of Ethics has come to be considered a masterwork of utilitarianism. Green endorsed Aristotle's view that life 'in a polis' is essential for us to become persons. He endorsed Aristotle's view that social institutions can have lasting effects upon the kinds of persons we become. With professionalization of the professorate continuing, the pressure to find ways to justify institutional recognition in the form of professorships, fellowships, independent departments, and/or tenure continued undiminished. A revival of interest in Aristotle's ethics followed, helped along by the appearance of Amelie Rorty's Essays on Aristotle's Ethics.