This text introduces and attempts to make clear and accessible—without denigrating their seriousness or difficulty—the most important principles for conducting any systematic philosophical inquiry, and therefore for building a serious philosophical habit. These principles are broken down into three sections: logic, physics, and person; or, the basic encounter with thought, with the world, and with the nexus of thought and world. Although the work draws on the traditions of Thomism, Semiotics, and Phenomenology, readers are not introduced to the history of philosophy in any tradition nor given extensive formal argumentation. Rather, this book is aimed at eliciting the habit of philosophical questioning: that is, the habit of routinely examining human life and the experiences had within it. In other words, this book provides a series of guideposts not only as to the kind of material you should engage if pursing a philosophical mentality, or the sorts of questions you should ask but to how the very process of philosophy is practiced. The deeper the reader goes into the text, the less likely will one find a complete or satisfying answer—but only more questions, with suggestions for how they might be asked in the right way.