ball quotes the 2nd edition's epigraph by the statistician karl pearson: "i believe the day must come when the biologist will—without being a mathematician—not hesitate to use mathematical analysis when he requires it." ball argues that thompson "presents mathematical principles as a shaping agency that may supersede natural selection, showing how the structures of the living world often echo those in inorganic nature", and notes his "frustration at the 'just so' explanations of morphology offered by darwinians." instead, ball argues, thompson elaborates on how not heredity but physical forces govern biological form. ball suggests that "the book's central motif is the logarithmic spiral", evidence in thompson's eyes of the universality of form and the reduction of many phenomena to a few principles of mathematics.