Most philosophical debate takes place between representatives of extremely opposing viewpoints. Through the long history of the discipline, these opposing positions have become quite well defined, even if somewhat loosely in certain cases. Part of the interest of contemporary philosophy derives from trying to state certain positions more clearly, using more recent methods or concepts. That is why so often, in the writings of contemporary philosophers, one detects an element of reprise, a hint of variation-on-a-well-known-theme, in the ideas being put forward. In broad terms, what they are claiming might well have been anticipated by some ancient, medieval, or early modern philosopher. The contemporary philosopher can plead, in mitigation, that there is somehow some new energy or interest in the view, given the more recently created conceptual materials being used to express it.