Philosophy investigates fundamental questions about the most basic facets of human thought and life, e.g., concerning knowledge and belief (epistemology), the nature of reality (metaphysics), and morality and aesthetics (value theory). Such questions can be studied by looking at answers that contemporary philosophers propose, by investigating the principles that other disciplines use to legitimate claims, or by learning how, historically, philosophers approached these issues. In this respect, “philosophy” names not only a historically defined subject matter, but also inquiry into any of the fundamental determinants of rational thought. Thus, students of philosophy can pursue a broad range of topics of the greatest historical, intellectual, social, political, and personal interest.