What does it mean to possess knowledge about something? What kinds of things exist and can be known? How should we live? What matters and what has value? In this book, we seek to answer these questions by examining contributions from the history of philosophy, science and ethics. The book has 20 chapters divided into three parts. Part 1, Knowing, asks questions about knowledge. Part 2, Being, starts by asking about what is real. Part 3, Doing, is devoted to ethics. Every chapter has an introduction and one or in some cases two original texts written either by contemporary thinkers or by important figures from the history of philosophy and science. Each chapter is accompanied by study questions and learning goals. The aim of this book is twofold: to teach you to become a critical reader, who can identify positions, arguments, and structures in a scientific text; and to introduce you to some important positions and ideas in order to enable you to discuss the big questions raised in the book.