This book contains a non-specialist introduction to modern physics and its formal and conceptual apparatus, with an emphasis on its philosophical aspects. It presents the development of the most important concepts and problems of physics, from ancient astronomical theories, through Newtonian mechanics, thermodynamics, the theory of electromagnetism, to both theories of relativity and quantum mechanics. It discusses in detail related philosophical questions, such as the issue of determinism and predictability, the dispute over the status of time and space, the ontological status of physical fields, and the testing and acceptance of empirical theories. The book can be useful to students of philosophy interested in the philosophical aspects of physical sciences, and to students of natural sciences who want to supplement their specialist knowledge with philosophical issues.