The primacy of experience denotes that knowledge derived first-hand is superior to knowledge derived second hand, which itself is superior to each subsequent passing. If techne is derived from experience than the loss of experienced practitioners limits the development of new techne that furthers the praxis. The primacy of perception in the propagation of preference makes all praxes Darwinian; each struggles for survival through the evolution of their techne for the attraction of practitioners. Potential practitioners must choose, amongst the offerings of their milieu, which if any praxes to pursue. Praxes that have developed and evolved with contemporary preference have a competitive advantage in their adoption and propagation; those that fail to evolve with contemporary preferences, or find stasis in declining ranks, are dying arts.