Foundations of Quantum Mechanics is written in simple and elegant style. Mathematical derivations are presented in complete detail with a lucid discussion of their physical significance. Symmetries inherent in quantum systems are brought out in a lucid way. Salient Features:* The first chapter provides a comprehensive presentation of the historical aspects of the development.* A brief review of classical mechanics is provided in the second chapter with a view to draw analogies between quantum and classical approaches wherever appropriate.* The third chapter introduces the Dirafunction and connection between Dirac function and Fourier transforms.* A formal conceptual basis for the understanding of the eigenvalue problems, properties of state and eigenvectors and their closure and completeness conditions-is laid in the fourth chapter.* Postulatory basis of quantum mechanics is discussed in Chapter 5 and one-dimensional problems in Chapters 6 and 8. A brief account of the WKB approximation is provided in chapter 7.* The central force problems are discussed with special emphasis on the hydrogen atom in Chapter 9.* The isotropic oscillator and its symmetries are discussed in Chapter 10.* Chapter 14 deals extensively with the theory of angular momentum, the spherical tensor operators and Wigner-Eckart theorem. The D-functions and their connection to spherical harmonics, integrals involving D-functions, the 3-j and 9-j symbols and their symmetry properties are also discussed.* Chapters 15, 16 and 17 are concerned with unitary transformations, Schrodinger, Heisenberg and interaction pictures, infinitesimal transformations and invariance properties of physical systems and symmetries of identical particles.* Relativistic quantum mechanics is presented in Chapter 18. Zitterbewegung, bilinear covariants, the one-electron problem, charge conjugation and whole theory are discussed in complete detail.