Kant’s No-Fap Rule Reveals the Secret of Morality

Not only in november

1. The Secret Joke of Kant’s Soul

Joshua Greene’s The Secret Joke of Kant’s Soul is a heavily cited paper, which means that most people into moral philosophy have read it, as opposed to the majority of other papers that exist.

Greene, a famous philosopher-neuroscientist hybrid sets out to answer a question: why was Kant so against masturbation?

To do so, he examines the psychological foundations of moral judgment by comparing two major ethical theories: deontology and consequentialism.

Greene argues that deontological judgments (morality based on norms, rights and duties) are primarily driven by automatic emotional responses—quick, intuitive reactions that don’t require much conscious thought. While consequentialist judgments (morality based on outcomes and consequences) rely on more cognitively expensive processes, such as deliberate reasoning and cost-benefit analysis.

To convince us of this Greene whips out a bunch of empirical evidence from neuroimaging studies, behavioral experiments, and psychological tests, demonstrating distinct neural correlates for each type of moral judgment. Regions of the brain linked to higher-order cognition—like abstract reasoning and deliberation—light up during consequentialist thinking, while “emotional centers” are more active when people consider duties, values, and moral norms.

Yes, we have been putting people in fMRI machines and asking them if they would push a man off a bridge to stop a runaway trolley

But wait what has all this to do with masturbation and Kant?

Well, Kant is the most famous deontologist, and one of the moral rules he took seriously—very seriously—was the no masturbation rule: that one should never, under any circumstances, engage in that kind of self-pleasure. Naturally, being a philosopher, he wasn’t content to simply declare masturbation immoral, he had to justify it.

But this, according to Greene, is where Kant reveals the secret of his soul.

2. Kant’s Argument Against Masturbation

So what is Kant’s argument against genital self-pleasure? Or, as Greene might be tempted to say, Kant’s “argument.” Here’s how Kant himself puts it:

That such an unnatural use (and so misuse) of one’s sexual attributes is a violation of one’s duty to himself and is certainly in the highest degree opposed to morality strikes everyone upon his thinking of it... However, it is not so easy to produce a rational demonstration of the inadmissability of that unnatural use, and even the mere unpurposive use, of one’s sexual attributes as being a violation of one’s duty to himself (and indeed in the highest degree where the unnatural use is concerned). The ground of proof surely lies in the fact that a man gives up his personality (throws it away) when he uses himself merely as a means for the gratification of an animal drive.

First Kant declares that masturbation strikes everyone as being wrong then he says that this must surely be because “a man gives up his personality when he uses himself merely as a means for the gratification of an animal drive.”

If this justification seems a bit strange to you, it’s because it is. What does using oneself as a means for the gratification of an animal drive mean exactly?

What about quenching thirst by drinking water—is that also immoral because we are using our mouth as a means to satisfy an animal drive? What about scratching an itch? It’s something purely physical, done for immediate relief and pleasure. What about humming a song because it feels nice?

A person throwing away their personality

More importantly, why is Kant, this philosophical titan of the past, offering a justification so prone to obvious objections and counterexamples?

Well, according to contemporary philosophy star Michael Huemer, it might be because many great philosophers of the past (Kant included) were “bad at thinking”.

My introduction to philosophy was largely through the great philosophers of the past -- the likes of Plato, Aristotle, Descartes, Hume, Kant. From the beginning, I was struck by how bad they were at thinking. Sometimes, they just seemed to be bad at logic, committing fallacies and non sequiturs that even an undergraduate such as myself could quickly see. Other times (almost always!), they seemed to have extremely poor judgment, happily proclaiming absurd conclusions to the world, rather than going back and questioning their starting points.

As a brief aside: when I first came across this idea, I was completely and utterly flabbergasted. After all, isn’t thinking about things literally the job of philosophers? In the following quote from Huemer, I was very much part of most people:

Not everyone realizes all this. Most people, I suspect, believe that the Great Philosophers are actually good at philosophy.

Other contemporary thinkers go even further than Huemer, suggesting that some of history’s celebrated thinkers may have, at times, been less than timeless geniuses and more peddlers of pseudo-profound nonsense.

When it comes to Kant, Greene is more gallant in tone than Huemer—but in terms of substance, his take isn’t all that different.

3. Greene Exposes the Secret of Kant’s Soul

Greene argues that while Kant tries to ground his prohibition in lofty appeals to personal dignity and self-respect, he admits that it's hard to produce a convincing rational demonstration for why masturbation is morally wrong. For Greene, this isn’t a trivial aside—it’s the giveaway. It’s the “emotional centers” lighting up in Kant’s brain generating the deontological intuition, not the regions dedicated to abstract reasoning. Indeed, what Kant sees as pure moral reasoning is, in fact, a post-hoc rationalization of emotional moral intuitions that Kant views as deriving from God.

You can’t really blame Kant for trying to rationalize his moral intuitions. His intuitions derive from his human nature (“the moral law within”), and ultimately from God. God’s a smart guy, Kant must have thought. He wouldn’t give people moral intuitions willy nilly. Instead, we must have the intuitions we have for good reasons. And so Kant set out to discover those reasons, if not by force of reason then by feat of imagination.

“Tell me more about your Lutheran upbringing.”

Greene doesn’t quite come out and say he’s psychoanalyzing Kant, but that’s effectively what’s happening. For him Kant is trying really hard to post-hoc rationalize the no-fap rule. The emotional intuition that masturbation is wrong comes first, and the high-minded rational justification gets built afterward to make it all look respectable—but it doesn’t hold up to much scrutiny.

In other words, Greene quietly and slightly more politely joins Huemer in the corner of those who think Kant is doing bad reasoning.

a) Nietzsche’s Remark on Kant

Greene’s backup doesn’t end with Huemer. To support his thesis he references the time Nietzsche claimed that the secret joke of Kant’s soul was that he wrote not against popular prejudices, but on their behalf.

“Kant wanted to prove, in a way that would dumbfound the common man, that the common man was right: that was the secret joke of his soul. He wrote against the scholars in support of popular prejudice, but for scholars and not for the people.” — Friedrich Nietzsche

According to Greene Nietzsche got it right: Kant’s complex and confusing moral reasoning was designed to defend common emotional intuitions rather than genuinely deriving moral conclusions from rational first principles. He took intuitive emotional reactions, polished them up, and presented them as if they were the product of pure reason. But they weren’t.

4. Greene Exposes Deontology

Empowered by his novel findings, Greene doesn’t want to limit himself at just critiquing Kant, his ambitions are greater. He suggests that because humans are emotional creatures prone to post-hoc rationalization, the way Kant approached morality isn’t some isolated quirk—it’s the mechanism by which much of deontological moral philosophy is generated in the first place.

We are now ready to put two and two together. What should we expect from creatures who (1) exhibit social/moral behavior that is driven largely by intuitive emotional responses, and (2) are prone to rationalization of their behaviors? The answer, I believe, is deontological moral philosophy.

Put less kindly, for Greene deontology stems from our remarkable ability to fool ourselves. We have a strong emotional reaction, and then we invent a principle to match it. Instead of admitting it's a baseless gut feeling, we construct a post-hoc rationalization and call it moral philosophy.

Deontology, then, is a kind of moral confabulation. We have strong feelings that tell us in clear and uncertain terms that some things simply cannot be done and that other things simply must be done. But it’s not obvious how to make sense of these feelings, and so we, with the help of some especially creative philosophers, make up a rationally appealing story: There are these things called “rights” which people have, and when someone has a right you can’t do anything that would take it away.

Needless to say, in philosophical circles, these are fighting words. Some deontologists were not amused. To which, some say, Greene replied: “Don’t get all emotional about it.”

5. Normative Implications

Toward the end of the paper, Greene asks himself whether his analysis has any normative implications. Do these scientific findings actually tell us something about how we ought to act? Greene thinks they do.

I believe that science does matter for ethics, not because one can derive moral truths from scientific truths, but because scientific, information can undermine factual assumptions on which moral thinking implicitly depends […] The relevance of science, then, is that it can tell us how our moral intuitions work and where they come from. And once we understand our intuitions a bit better we may view them rather differently.

So where do deontological intuitions come from? Greene suggests they originate from evolved psychological drives—like the impulse to punish wrongdoers, or the tendency to care more for those who share our genetic background.

We have inferred on the basis of the available evidence that the phenomenon of rationalist deontological philosophy is best explained as a rationalization of evolved emotional intuition.

According to a philosophical vermin (me), this is one of Greene’s weaker points. It seems pretty clear that many deontological intuitions aren’t just evolved—they’re learned. Take Kant, for example. Greene himself recognizes that his moral instincts are likely due to his strict Lutheran upbringing, not evolution.

But Greene wants to argue that because deontological intuitions often stem from blunt biological facts, this spells trouble for their credibility as moral judgments. They’re not glimpses into moral truth; they’re artifacts of evolutionary wiring. In Greene’s view, that makes them epistemically suspect—products of natural selection, not reason. In other words, evolutionarily debunked.

While the mighty consequentialism appears to carry more moral weight

This is in contrast to consequentialism, which, I will argue, arises from rather different psychological processes, ones that are more “cognitive,” and more likely to involve genuine moral reasoning.

6. The Secret of Greene’s Soul

In the final paragraphs of the paper Greene becomes self-aware and troubled by the evolutionary debunking argument he just used to critique deontology.

Taking these arguments seriously, however, threatens to put us on a second slippery slope (in addition to the one leading to altruistic destitution): How far can the empirical debunking of human moral nature go? If science tells me that I love my children more than other children only because they share my genes (Hamilton, 1964), should I feel uneasy about loving them extra? If science tells me that I’m nice to other people only because a disposition to be nice ultimately helped my ancestors spread their genes (Trivers, 1971), should I stop being nice to people? If I care about my self only because I am biologically programmed to carry my genes into the future, should I stop caring about myself? It seems that one who is unwilling to act on human tendencies with amoral evolutionary causes is ultimately unwilling to be human. Where does one draw the line between correcting the near-sightedness of human moral nature and obliterating it completely?

Greene would like to immunize consequentialist moral reasoning from the same evolutionary debunking argument he uses to vanquish deontology. But he’s too smart not to see where that road leads. It doesn’t matter much that consequentialist intuitions involve “genuine moral reasoning” or that they arise from different cognitive processes. They’re still cognitive processes—still shaped by evolution—and therefore, just as vulnerable to the same kind of debunking.

Greene seems to recognize this, which is probably why he chooses to close the paper with the final passage quoted above—leaving the question hanging, rather than stepping into the same trap he just sprung on deontology.

Nonetheless, Greene is right to note that evolutionary debunking arguments raise questions of their own. One that I find especially pressing is this: if evolution endowed us with certain moral predispositions, why should we trust—or care about—other ones?

The evolutionary debunking point of view seem to smuggle in the assumption that there are alternative moral facts out there, somehow more “real” or trustworthy. But how exactly are we supposed to access them? Through what—some kind of non-evolved moral perception module? A built-in truth-tracking moral compass evolution forgot to tamper with?

There’s something a little suspicious about this setup.

But unfortunately for Greene, without the evolutionary debunking card, he loses the very tool he was using to undermine deontology. The upper hand slips away.

7. A Stronger Argument for Consequentialism?

After finishing his paper, Greene must have sensed that his neuroscience research pointed toward an even stronger argument. Indeed, in a subsequent article, he expands on his ideas and suggests that it’s reasonable to think of deontological intuitions as fast, automatic System 1 heuristics, while consequentialist judgments are the slower, more deliberate product of System 2 thinking—the brain’s manual mode.

This leads him to argue that “we should distrust our automatic settings and rely more on manual mode when attempting to resolve practical moral disagreements.” But perhaps we can take this one step further still.

If we recognize that, according to modern psychological theories, many cognitive biases arise from system 1 processes as quick heuristics to save mental resources, we can begin to sketch a hierarchy of moral judgment.

Given that evaluating the full consequences of our actions is computationally expensive, deontological instincts appear to have evolved as fast, efficient shortcuts—rules of thumb that generally lead to good outcomes without requiring complex moral calculus. But what are they shortcuts towards? Well, they would be shortcuts towards the more cognitively demanding “manual mode” given by consequentialism.

Under this view, deontology isn’t a rival to consequentialism, but a practical proxy. Deontological principles act as quick and efficient ways to achieve good outcomes in practice—rules, norms and values that operate in service of the deeper moral system they’re approximating: consequentialism.

In the end, to highlight the significance of consequentialism, Greene didn’t need to debunk deontological intuitions, just show their actual purpose.