Maurice Anthony Biot was not only the scientific founder of earthquake engineering. His pioneering contributions extended well beyond, to many other fields, including mechanics of porous media, wave propagation, aerodynamics and aeronautic fluid mechanics, non-linear elasticity, theory of folding and thermodynamics. Combin- ing simplicity and breadth, his work achieved the aesthetic qualities displayed by foremost nineteenth century and turn of the century practitioners of mathematical physics like Maxwell, Rayleigh and Sommerfeld. In the following we review only Biot’s contributions to earthquake engineering, the first steps, the background, the time in which he grew and several other factors, which may have influenced him and contributed to his formulation of the response spectrum method. Today, Biot’s response spectrum method continues to be the basis for all modern seismic design work, a condicio sine qua non in all of earthquake engineering.