A compilation of previously unpublished lectures delivered at the International Centre for Theoretical Physics by the pioneers and creators of modern physics –Bethe, Dirac, Heisenberg, Wigner, Klein and Landau (the sixth delivered by E Lifshitz). By sharing with us their own lives of physics, these outstanding physicists convey the sense of total dedication, the pleasure and elegance of scientific creation at its peak. Readers would acquire a deeper sense of the scope and nature of physics, and the insights of its fascinating diverse disciplines as the developments of modern physics are being unfolded through history.