The argument from desire is an argument for the existence of God. The argument was widely used by noted Christian apologist and author C. S. Lewis, and played a part in his conversion from atheism to Christianity.

The argument, as summarized by Peter Kreeft, can be expressed as follows:

1. Every natural, innate desire in us corresponds to some real object that can satisfy that desire.
2. But there exists in us a desire which nothing in time, nothing on earth, no creature can satisfy.
3. Therefore, there must exist something more than time, earth and creatures, which can satisfy this desire.
4. This something is what people call "God" and "life with God forever."

A distinction is made between the two different types of desire, the innate and externally conditioned, or natural and artificial. Natural desires, such as the desire for food, drink, or sleep, come from within us. They also exist in all of us, but the artificial ones vary from person to person.

C. S. Lewis summarized it in this way:

Creatures are not born with desires unless satisfaction for these desires exists. A baby feels hunger; well, there is such a thing as food. A duckling wants to swim; well, there is such a thing as water. Men feel sexual desire; well, there is such a thing as sex. If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world. - Mere Christianity, Bk. III, chap. 10.