Bob's blog – A skeptical lawyer

C.S. Lewis’ Argument from Joy – I desire a more scientific argument

Posted on January 4, 2019


Homer Simpson gave Bart some fatherly advice worth remembering. “The three little sentences that will get you through life… Number one. Cover for me. Number two. Oh, good idea boss. Number three. It was like that when I got here.” In this post, I’ll use the third sentence.

Although you may find this discussion about the “argument from desire” to be both complicated and dull, the subject matter was already like that when I got here. I try write interesting posts, but this one is not an easy read. I welcome anyone to comment with constructive criticism.

Medieval logic

Theologians developed the “argument from desire” during the Middle Ages. Thomas Aquinas argued that man has natural desires that cannot be fulfilled in this life and that these desires must be fulfilled after this life.[1] Otherwise these unsatisfied desires would be pointless, and that would violate Aristotle’s axiom that “nature does nothing in vain.”

The argument from desire fell out of favor because modern apologists do not usually rely on Aristotle. C.S. Lewis, a scholar of medieval literature, retrieved this questionable idea from the medieval dustbin. Lewis never wrote a definitive treatise on the argument from desire, but he returned to the subject repeatedly in various books and articles.

Like Aquinas, Lewis’ argued for the existence of a desire that cannot be satisfied in this world. In Mere Christianity, Lewis explained that unsatisfied desires support God’s existence because:

Creatures are not born with desires unless satisfaction for those desires exists. A baby feels hunger: well, there is such a thing as food. A duckling wants to swim: well, then; 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.”

In other words, people and animals feel innate desires for things that are real, so Lewis’ desire for another world means that other world is real. However, Lewis was rather imprecise about  exactly what unsatisfied desire formed the basis of his argument.

In Surprised by Joy, published a decade after Mere Christianity, Lewis describes how he spent much of his early life in pursuit of “joy.” By “joy,” Lewis does not mean happiness or pleasure. Instead, Lewis’ “joy” is “an unsatisfied desire which is itself more desirable than any other satisfaction.”[2] Lewis uses “longing” or the German word “sehnsucht” synonymously with “joy.”

Lewis never used the terms “argument from desire” or “argument from joy.” However, many apologists call Lewis’ version of the argument from desire the “argument from joy” because “joy” seems to be the unsatisfied desire upon which Lewis bases his argument.

Philosopher Dr. John Beversluis critiqued Lewis’ apologetics in C.S. Lewis and the Search for Rational Religion, first published in 1985 and revised in 2008. Church of Christ minister Joe Puckett responded to Beversluis’ criticisms in his 2012 book, The Apologetics of Joy: A Case for the Existence of God from CS Lewis’s Argument from Desire. I have read neither of these books because I don’t care to read two books on what I consider to be a very unscientific argument. Likewise, I have not delved into arguments based on other desires, such as a supposed desire for perfect beauty. I think the sources I cite in this post enable me to understand the gist of the issue. Please comment with your own thoughts.

Deductive argument

Apologists disagree whether the argument from desire is a deductive or inductive argument. A deductive argument deduces a conclusion from two or more premises. The deduction is valid only if the premises are valid. Aristotle defined the classic deductive syllogism, which uses a major premise (a general statement) and a minor premise (a specific statement) to deduce a conclusion.

Major premise:     All men are mortal.
Minor premise:     Socrates is a man.
Conclusion:          Therefore, Socrates is mortal.

Peter Kreeft, a professor of philosophy at Boston College, frames the argument from desire as a deductive syllogism.

Major premise:     Every natural, innate desire in us corresponds to some real object that can satisfy that desire.
Minor premise:     But there exists in us a desire which nothing in time, nothing on earth, no creature can satisfy.
Conclusion:          Therefore there must exist something more than time, earth and creatures, which can satisfy this desire.

Apologist Robert Holyer recognizes that the argument from joy fails as a deductive argument.[3] Beversluis identified the pivotal issue: “How could Lewis know that every natural desire has a real object before knowing that Joy has one?” In other words, the deductive syllogism begs the question

Kreeft recognizes this criticism: “How can you know the major premise—that every natural desire has a real object—is universally true, without first knowing that this natural desire also has a real object? But that is the conclusion. Thus you beg the question.” Kreeft responds that his first premise is a “universal truth” similar to “All men are mortal.” Kreeft further reasons:

We can and do come to a knowledge of universal truths, like “all humans are mortal,” not by sense experience alone (for we can never sense all humans) but through abstracting the common universal essence or nature of humanity from the few specimens we do experience by our senses. We know that all humans are mortal because humanity, as such, involves mortality, it is the nature of a human being to be mortal; mortality follows necessarily from its having an animal body.

Kreeft’s “universal truths” sound  similar to scientific truths. However, Kreeft never explains  any scientific truth  or “common universal essence or nature of humanity” to support his major premise – that every natural, innate desire in us corresponds to some real object that can satisfy that desire.

Inductive reasoning  and the scientific method

Although most apologists agree that Lewis’ argument from joy fails as a deductive argument, some believe it succeeds as an inductive argument.  Inductive reasoning makes generalizations based on specific observations. There are several types of inductive reasoning,  but apologists never specify exactly what kind they rely upon. For example, Holyer’s version of the inductive argument from joy goes something like this:

Major premise:     Most natural desires have existing objects that they are desires for.
Minor premise:     Joy – a desire for an infinite object –  is another natural desire.
Conclusion:          Therefore, an infinite object probably exists.

This appears to be a “simple induction.” A simple induction uses the following reasoning.

Major premise:     Most members of population P have attribute A.
Minor premise:     Individual is another member of population P.
Conclusion:          Therefore, individual probably has attribute A.

I can use simple induction to predict that gopher wood will probably float in water. I have observed that pine, oak and many other types of wood all float, so I can predict that gopher wood would probably float. However, I might be wrong because some wood, called ironwood, sinks in water.

Science reveals why most wood floats. Objects float in water if they are lighter than water. Water weighs 1 g/cm³. Ironwood sinks because it is heavier than water.  If I had a piece of gopher wood, I could measure its weight and volume, and then calculate whether it is lighter or heavier than 1 g/cm³.

Science allows us to make better predictions than simple induction. With that in mind, let’s look at the inductive argument from joy – step-by-step.

Major premise:    Most members of population P have attribute A.
                              Most natural desires have existing objects that they are desires for.

Apologists argue that people may learn all sorts of unnatural desires, but they only feel innate desires (desires they are born with) for things that actually exist. In general, I believe that to be true, but for reasons that do not support the argument from desire.

Innate desires for things in the real world make sense from an evolutionary standpoint.  Animals evolve characteristics related to the real world. Air exists in the real world, and birds evolved wings to fly in it. Water exists, and fish evolved fins to swim in it. Natural desires also evolved in relation to things that actually exist.

Hunger and thirst motivate animals to eat and drink – activities essential to survival. Instincts, such as baby ducks wanting to swim, also motivate behaviors that are likely to increase an individual’s chance of living long enough to reproduce. From a scientific standpoint, it makes sense humans and animals have natural desires for things that exist.

Evangelicals reject evolution and claim God gave creatures natural desires. However, assuming that God gave creatures natural desires makes the argument from joy a circular argument – an argument in which a premise assumes the truth of the conclusion.

Major premise:     God gave creatures natural desires for existing objects.
Minor premise:     God gave humans joy – a desire for God.
Conclusion:          Therefore, God exists.

God must exist in order to give creatures natural desires, so claiming God gave creatures natural desires cannot prove God’s existence.

Minor premise:    Individual is another member of population P.
                              Joy – a desire for an infinite object – is another natural desire.

Unlike some of my fellow skeptics, I will not question that joy is a real desire. Lewis said he experienced it, and I do not doubt his truthfulness.  However, I question his logic.

The basic idea behind inductive reasoning is that we can observe some members of population and extrapolate to other members of the population. This only makes sense if we have a clearly defined population. For example, ironwood is clearly a type of wood – it comes from trees.

“Natural desires” is a heterogeneous and unscientific definition for a population. Hunger, thirst, and sexual desire are each unique and different from each other. So far as I can determine, other innate desires (such as a baby duck’s desire to swim) are instincts. Although they have little in common with each other, at least these desires are familiar to most people. Ask any of your friends about hunger, thirst, sexual desire or fear of snakes (a human instinct), and they will know what you’re talking about.

I cannot see that Lewis’ “joy” or sehnsucht belongs in the same group as these familiar feelings. Lewis’ “joy” is so uncommon and esoteric that we do not have a word for it in English. I read Surprised by Joy cover to cover, and I’m still not sure exactly what Lewis meant by “joy.”

Conclusion:          Therefore, individual probably has attribute A.
                              Therefore, an infinite object probably exists.

The final irony in the argument from joy is that apologists in general and Lewis in particular do not like either deductive or inductive reasoning applied to Jesus.

Kreeft considers it a universal truth that “all humans are mortal.” Jesus was human, therefore we should be able to deduce that Jesus was mortal. Likewise, billions of people have died, and none of them have been observed to rise from the dead. Therefore, we can make the inductive generalization that no one rises from the dead. Of course, apologists reject these conclusions.

Lewis rejected inductive reasoning when he did not like the result. While defending Jesus’ resurrection from such inductive generalizations, Lewis claims that, because “the principle of Uniformity of Nature” is philosophically unsound, “the fact that a thing had happened ten million times would not make it a whit more probable that it would happen again.”[4] By that logic, ten million desires correlated to ten million existing objects would not make it a whit more probable that joy correlates to an existing object.

[1] Thomas Aquinas, Contra Gentiles, Book 3, Chapter 48 (That Man’s Ultimate Felicity Does Not Come in This Life), section 10-11.

[2] C.S. Lewis, Surprised by Joy 17-18 (Harcourt, Brace and World, Inc. 1966).

[3] Robert Holyer, The Argument from Desire, page 68.

[4] C.S. Lewis, Miracles 162 (HarperOne 2001).