 He then suggests that there is no empirical difference between these statements, and says that they differ in "metaphor" and "sociological or polemical viewpoint".He argues that "the paradigms for genetic causality in biological systems are seriously confused" and that "The metaphors that served us well during the molecular biological phase of recent decades have limited or even misleading impacts in the multilevel world of systems biology.New paradigms are needed if we are to succeed in unravelling multifactorial genetic causation at higher levels of physiological function and so to explain the phenomena that genetics was originally about."