This minority has a number of options. One is to hold that conscious properties are "epiphenomenal" and do not exert any influence on brain processes or subsequent behaviour (Jackson 1982, 1986; Chalmers 1996).[9] Another is to embrace the "overdeterminationist" view that the physical results of conscious causes are always strongly overdetermined , both by their normal physical antecedents and by the metaphysically independent conscious causes (Mellor 1995, Kroedel 2015). Still, neither of these positions is attractive. They require us to posit odd causal structures, either involving a species of effects that are never themselves causes, or a species of effects that are always strongly overdetermined. Given that nature displays no other examples of such causal structures, general principles of theory choice would seem to argue against both epiphenomenalism and overdeterminationism.