Rolf-Peter Horstmann

This book examines the presence of idealism in modern philosophy from the seventeenth century to the turn of the twenty-first. We define idealism proper as the position that reality is ultimately mental or conceptual in nature, to be contrasted to materialism or physicalism. So defined, idealism has hardly been a popular view, at least in the twentieth century. But we distinguish between metaphysical and epistemological arguments for idealism, and argue that while the former have rarely been popular, the latter are so, and present in many philosophers who would hardly call themselves idealists. We conclude that metaphysical arguments in favor of a reduction of all reality to either mind or matter are highly questionable, because we have no reason to believe that we have arrived at an adequate understanding of either. However, epistemological arguments in favor of idealism that point to some version of conceptual idealism or other are indeed difficult to avoid.