Fröhlich's coherent excitations & the cancer problem--a retrospective overview of his guiding philosophy.

The guiding philosophy underlying Fröhlich's approach to biology from the side of theoretical physics is summarized, and illustrated, in the context of his prediction of (dynamic) coherent excitations in living systems, based on their dielectric and elastic properties, and far-from-equilibrium (nonlinear) character. His envisaged role of these coherent excitations in cell division and its control is outlined, together with the associated implications for cancer--as understood both at the time of his work and subsequently.