It seems that counterfactuals and many other statements are subject to semantic underdetermination. Classical logic pushes one to an epistemicist account of this underdetermination, but epistemicism seems implausible. However epistemicism can be made plausible when conjoined with a divine institution account of meaning. This gives us some reason to accept that divine institution account, and hence some reason to think that God exists. This chapter evaluates the arguments for epistemicism and divine institution, including objections, and incorporates Plantinga’s consideration of counterfactuals when it comes to theism. In particular, an analogy is drawn with divine command and natural law theories in ethics.