Abstract. On the naive reading, “radical social constructivism” would be the result of “deconstructing” science. Science would simply be a contingent construction in accordance with social determinants. However, postmodernism does not necessarily abandon fidelity to the objects of thought. Merold Westphal's Derridean philosophy of religion emphasizes that even theology need not eliminate the transcendence of the divine other. By drawing an analogy between natural and supernatural transcendence, I argue that science is similarly called to responsibility in the encounter with that which lies outside its horizon of expectation. Science's rational autonomy is overcome by the heteronomy of realities that precede it. Understanding species as homeostatic property clusters is an example of nonessentialist, postmodern, and scientific realism. Science is still a vehicle for encountering natural alterity, thus decentering the relativism thought to characterize postmodernism. However, natural science must not attempt to place the whole of being at human disposal if it is to fulfill the potential of Westphal's philosophy of religion.