The ‘Horseshoe Theory’ is the idea that the more extreme the political left or right become the more they resemble each other. According to this view, the extreme left and the extreme right, rather than being opposing ends of a linear political spectrum, would therefore actually sit close together and promote systems with important similarities – analogous to the way that the opposite ends of a horseshoe are close together. The extreme left of Joseph Stalin and the extreme right of Adolph Hitler, for example, share distinct similarities and were both delineated by being totalitarian regimes that persecuted specific social groups. The horsehoe theory was defended by many authors and political scientists, among them Jean-Pierre Faye and Jeffrey Taylor.