The exogenous and endogenous types of relationships between ethics and economics are explained in neoclassical and non-neoclassical frameworks. Market consequentialism, deontological preferences and polity-market (ecology) interactions are brought out to configure the theoretical perspectives of the endogenous theory underlying the interface between ethics and economics. The principle of ethical endeogeneity is treated in an institution-economy interface by addressing the issue of sustainability. In this respect a simple mathematical formulation is done to show how ethics can be endogenized in a scientific framework for theory, policy development and institutionalism. Critically examines Canada's Green Plan in light of the exogenous and endogenous ethical relationships. Develops the critique and proposes ethico-economic policy-theoretic alternatives.