``From the above account, it is clear that every conceptual element in Cauchy's theory was to be found in one or another of the special theories constructed in the previous century. Moreover, in researches of Fresnel done in 1821--1822, with which Cauchy must certainly have been familiar, many of Cauchy's results are more or less implied, although in Fresnel's work the concepts of stress and strain are always connected through a presumed linearly elastic response.Thus it might seem that Cauchy's achievement in formulating and developing the general theory of stress was an easy one. Cauchy's concept has the simplicity of genius. Its deep and thorough originality is fully outlined only against the background of the century of achievement by the brilliant geometers who preceded, treating the special kinds and case of deformable bodies by complicated and sometimes incorrect ways without ever hitting upon this basic idea, which immediately became and has remained the foundation of the mechanics of gross bodies.
Nothing is harder to surmount than a corpus of true but too special knowledge; to reforge the tradition of his forebears is the greatest originality a man can have.''
From pp. 236, 238 of C. Truesdell, ``The Creation and Unfolding of the Concept of Stress'', Essays in the History of Mechanics, Berlin: Springer-Verlag, 1968, pp. 184-238.