With Theoretical Kaleidoscope, by Iosif Khriplovich, many concrete problems in classical mechanics, classical electrodynamics, quantum mechanics, and relativistic quantum mechanics are solved. This book is not a systematic course on theoretical physics. Rather, it uses intuitive, qualitative arguments to solve selected problems of this remarkable science. The book is based on lectures given by the author over many years. The main source of problems addressed in the book are taken from the author's own investigations, as well as discussions with colleagues and students. With this book, the author hopes readers will be able to see the examples and engage in thoughtful discussions and arguments of their own. Topics discussed in this book include: Theoretical Kaleidoscope is intended for students and physicists, both theoretical and experimentalist, and those who will appreciate seeing theoretical physics through innovative qualitative analysis.