 Plato and Aristotle can in many ways be seen as defending some fundamental tenets of Greek ethics (such as the value of justice), but doing so by means of advancing revisionist philosophical doctrines and distancing themselves from the ways in which those tenets were interpreted by the democratic institutions of their day. The range of ethical and political views which they, along with their Hellenistic successors, laid out, continue to define many of the fundamental choices for modern philosophy, despite the many important innovations in institutional form and intellectual approach which have been made since. Many of those innovations, indeed, came in response to a revival of the ancient skeptical and relativist challenges: challenges already known from their evolution within ancient political philosophy itself.