In his apologetic writings, C.S. Lewis often wrote about the human longing for something beyond the material world. He saw in every heart a desire no earthly experience can satisfy, which he describes as an “inconsolable longing” for transcendence, ultimate justice, and eternity. For Lewis, this unfulfilled hunger – this “something more” – was evidence that we were made for another reality.

His argument rests on a principle of correlation. In our world, innate, universal appetites correspond to real fulfilments. We observe that nature does not, as a rule, contain creatures with built in, instinctual needs unless a corresponding fulfilment for those needs exists. We experience hunger because food exists. We feel thirst because water exists. The existence of the desire points quite reasonably to the existence of its object. Lewis distinguishes these universal needs from specific, individual wishes. A person might wish to fly unaided, but this is not a universal, innate hunger. The appetite for God, Lewis argues, falls into the innate category, alongside hunger and thirst. He suggests it would be a unique and strange exception if humanity universally possessed a powerful and fundamental appetite for which no satisfaction was possible.

Consider a world where creatures possessed an appetite for food but had no mouth, no stomach, or in which the very concept of “food” did not exist. This scenario describes something far stranger than mere famine. It describes a world where an appetite exists for which there is no capacity for fulfilment. The very existence of hunger would be a biological absurdity and a meaningless torment built into a creature for no purpose, in a universe without sustenance. Such a feature would serve no biological purpose and would be a detrimental flaw.

Lewis applies this logic to the human desire for the transcendent. We seem to possess a deep-seated appetite for the divine, for morality, and for an eternal reality. If no such reality exists, then this appetite is a cruel anomaly. It would mean we are built to crave something that is not merely absent, but fundamentally impossible. It would make our deepest longings as absurd as an appetite for food in a world without digestion.

Some argue this desire is nothing more than a psychological projection to soothe our fear of death. Lewis counters this by noting that the existence of a desire does not disprove the existence of its object. A person starving in a desert certainly wishes for water, but that wish does not mean water is a hallucination. In fact, the capacity to feel thirst is evidence that water exists. The question is not whether we wish for God, but why we have this specific, universal appetite in the first place.

This appetite for the transcendent becomes nothing more than a detrimental abstraction if we live in a purely material world. It would be a constant source of dissatisfaction and a fundamental design flaw pointing to nothing. It would make us constitutionally unsuited for the only reality available to us. Lewis argues that the most reasonable conclusion is that the appetite exists precisely because its object exists. Just as hunger points to food, the innate human desire for God points to God.