Warrant and religious belief › Proper function and a design plan

The expression design plan can sound as though Plantinga begins by assuming a divine designer. He explicitly says that the notion is not initially meant to entail conscious creation. It concerns how a system is supposed to function. Whether natural processes can adequately account for proper function is a further philosophical question.

His account can therefore be introduced before the specifically theological model. Consider the difference between a device operating according to its intended function and a device producing the same output through a fault. That comparison helps explain the distinction, though a manufactured device is not a full theory of human cognition. Plantinga's claim concerns cognitive faculties and the conditions for their epistemic success.

The theological model then supplies a particular account of those capacities. On that model, God creates human beings capable of knowing aspects of reality, including God. The model's theological commitments do substantive work. They are not a conclusion established merely by defining proper function.

Plantinga's theory is externalist in an important sense: warrant can depend on facts about how a belief was produced that the believer need not first establish by argument. A person can know through perception without possessing a philosophical theory of perception. This does not remove reflection from epistemic life. It distinguishes possessing knowledge from being able to defend a general account of how knowledge is possible.