A thorough, reflective survey of the life and work of this theoretical astrophysicist. Early life and education in India, 1910-1930, and experiences at Trinity College, University of Cambridge, 1930-1937, with comments on Edward A. Milne and Arthur S. Eddington; debate with the latter over collapse of white dwarf stars. Move to U.S. in 1937, with comments on the situation at Harvard and Princeton Universities since the 1930s, and especially on Henry N. Russell, John Von Neumann, and Martin Schwarzschild. Social context at University of Chicago and Yerkes Observatory since 1937, with remarks on Gerard Kuiper, Otto Struve, Bengt Strm̲gren, etc. Work as teacher there, and as editor of Astrophysical Journal from 1951 until it was given to the American Astronomical Society in 1971. Scientific work resulting in Introduction to the Study of Stellar Structure (1939) and publications on stochastic processes in galaxy and in general, radiative transfer, interstellar polarization, hydrodynamics and hydromagnetics (including experimental checks). Recent work on general relativity and Kerr metric; comments on cosmology. General remarks on the social structure of astronomy and its cultural role. Extended discussion of his way of functioning as a theorist. Also prominently mentioned are: Hans Albrecht Bethe, Paul Adrien Maurice Dirac, Enrico Fermi, Ralph Howard Fowler, George Gamow, Robert Hutchins, James Jeans, Alfred H. Joy, William Wilson Morgan, Harry Hemley Plaskett, Sir Chandrasekhar Vankata Raman, Ernest Rutherford, Harlow Shapley, Arnold Johannes Wilhelm Sommerfeld, Lyman Spitzer, Eugene Paul Wigner; Aberdeen Proving Ground, American Astronomical Society, Presidency College (Madras), United States Office of Naval Research, and United States Proving Ground at Aberdeen MD Ballistics Research Laboratory.