A polymath of a kind now seemingly extinct, with sensitivities to both the scientific and humanist traditions, von Bertalanffy's early work was devoted to fighting vitalist misconceptions that life was contrary to physics. To modern eyes, his theoretical biology seems more philosophical biology† while his studies of the kinetics of open systems were overshadowed by Onsager and Prigogine's development of the thermodynamics of open systems‡. His later attempts to extend systems thinking outside biology acquired a predictably enthusiastic following but the legacy of General Systems Theory§ has been insubstantial.
†L von Bertalanffy, Modern Theories of Development - An Introduction to Theoretical Biology, OUP 1933.
‡L von Bertalanffy, "The theory of open systems in physics and biology", Science 111:23-9 1950.
§L von Bertalanffy, General Systems Theory: Foundations, Development, Applications, George Braziller, 1968.