Monday, May 31, 2010

What Is My Purpose?

You've probably asked yourself the question, "What is my purpose?" Most people do, and then they die without ever hearing a satisfying answer. Others latch on to some arbitrary answer and feel like their curiosity has been sated, even though it hasn't really been fed.

It's easy to see that the question can be asked more precisely. You probably want an answer that was determined before you were born, right? By an entity that can be said to have "created" you in some sense? OK, we can work with that.

If you're in the habit of asking such "deep mysterious questions", you'll notice that it usually doesn't make sense to try to answer them as they are posed. Instead, the way to make the mystery go away is to explain what happens in your brain that makes you feel such a question is meaningful to pose.

Your brain generates questions to fill in gaps in your mental model of the world. But sometimes you start with an inaccurate mental model. So when you ask a question that makes sense to you, it doesn't necessarily constitute a meaningful question about the world.

In this case, the inaccurate mental model at fault is the concept of "purpose". Human thoughts are constructed out of building blocks that are hardwired into our brain. Our intuitive ontology includes concepts like "object", "momentum", "mood", and in particular, "purpose".

Our intuitive notion of purpose isn't perfect, as I will explain, but it is tied to meaningful observations. For example, we correctly intuit that a sundial is a lot more "purposeful" than a pile of rocks. That's because, in order to judge "purposefulness", we subconsciously make a distinction about why each thing exists:

  • Pile of rocks: Because of a passive physical process.
  • Sundial: Because of an optimization process.
If you'd never seen a sundial, and one day you saw one standing next to a pile of rocks, right away you'd subconsciously put it in the second category, because it's too improbable to be in the first. The best hypothesis to explain your observation, the one that most accurately predicts the existence and properties of sundials, posits the existence of a process that tries to "optimize toward a time-telling objective".

Even if you'd never heard of a sundial, and you didn't know about the time-telling objective, you would subconsciously assume that there's some criterion the sundial satisfies, and that some "optimization process" out there only creates things that satisfy that criterion. We're programmed, correctly, to conclude there's an optimization process at work when we see something that looks a lot more improbable than a pile of rocks.

When we detect an optimization process at work, we intuitively model it as if it's like a person who is consciously trying to achieve a goal. This works perfectly when the optimization process at work is, in fact, a person, like in the case of the sundial. But our intuition is completely unprepared to reason about an optimization process that isn't human-like.

A prestigious group of philosophers famously fell victim to their flawed intuition about optimization processes, and all their publications became contaminated with the assumption that optimization can only be performed by a purposeful human-like entity. I am talking about everyone before Darwin.

Before Darwin, people's intuitive purpose-o-meter was well-calibrated when it came to sundials and rocks. But the level of optimization evident in life forms registered off the charts, and people intuited that whatever created them must have had one hell of a purpose. The famous "argument from design", believed by everyone from Socrates to modern creationists, goes like this:

  • Boy, life forms sure are optimized to satisfy certain criteria really well.
    [Accurate observation.]
     
  • They couldn't have been made by any old process; it had to be an optimization process.
    [Sound intuitive inference.]
     
  • Life was created by a process involving a purposeful designer.
    [Unsound intuitive inference.]
Before Darwin, everyone knew about the biological processes of variation, reproduction and death. But all those things were filed under the mental category of "passive physical process". Darwin realized that a combination of those passive physical processes leads to Natural Selection. And Natural Selection is a process that only creates things that satisfy the criterion of reproductive fitness. And that means it belongs in the other mental category: "optimization processes".

But human intuition isn't having any of this. Intuitively, "passive physical process" and "optimization process" are two fundamental mental categories, and it's inconceivable that you could build an optimization processes out of a combination of processes that are not themselves optimization processes.

This is one of the most common patterns in the history of scientific progress. Someone will say "Hey, what if Y is made out of this other thing X, even though X by itself is nothing like Y?" And your intuition will say, "Nope, trust me, Y is ontologically fundamental, so no insights here." For example:

  • Your intuition thinks sound is a fundamental thing, and wind is another fundamental thing, but really they are both properties of the movement of air particles.
     
  • Your intuition thinks motion and rest are two fundamentally different things, but really the only difference is your choice of reference frame.
     
  • Your intuition thinks your hand is made out of special organic matter whose mysterious life force makes it obey your mental commands, while a lump of clay is made out of boring regular matter. But really the only difference is that your brain controls muscles in your hand through a big wire.
A related pattern is that when you don't understand some phenomenon, it often feels like a grand irreducible mystery. Most of your ancestors were completely ignorant about science, so your intuition is only expecting to hear stories that "explain" a phenomenon while keeping the mystery intact, and without actually increasing your ability to make predictions about it. The last thing you expect is for the mystery to be explained in terms of non-mysterious concepts. But that's what Darwin did for the origin of life, and the explanation for your "purpose in life" curiosity will follow as a corollary to Darwin's insight.

Remember that any time you observe optimization, like with the sundial, you immediately make a mental model of an optimizer that possesses human-like purpose. You subconsciously observe lots of optimization in yourself and others, so you conclude you were created by a process with a human-like purpose. You want to complete the analogy: "Sundial is to time-telling as I am to ______".

If you fill in the blank with "perpetuating the relative frequency of certain alleles in the gene pool", then the analogy is a logical one. But even with our post-Darwinian understanding, which enables us to complete the analogy, it still doesn't feel like the mysterious question has been adequately explained away.

Why doesn't anyone actually try that hard to perpetuate their genes? People have a lot of sex, but they use birth control. People have kids, but not that many. And why do sperm banks have to pay men, instead of the other way around?

It's because perpetuating your genes isn't your purpose. It's your creator's optimization criterion, but it's not your purpose. You have your own purposes.

If you were creating an entity, and your purpose was to perpetuate its set of genes, and you were going to make that entity conscious, then wouldn't you make your creation consciously want to perpetuate its genes? That's the smart thing to do.

But the process that created you is pretty stupid. It pushes toward genetic fitness, but it doesn't do it perfectly. In fact, there are all kinds of obvious ways to make its creations more fit, but they're only "obvious" to a smart process like your brain. The only changes that are obvious to natural selection are the ones caused by minor mutations to the alleles in the current gene pool.

You are the product of a creator that did an impressive, yet also pathetically bad, job of optimizing you to perpetuate your genes. If Natural Selection were smart, it would have created you with one single, unshakable purpose: to perpetuate your genes. But it didn't. What purposes did it give you instead?

Well, it was trying its best to program a gene perpetuation purpose into the human brain, but it could only do a little bit in each generation. What we ended up with is a variety of impulses, some contradictory, and none of them explicitly representing the desire to perpetuate genes (although the desire to have kids comes close) -- but all of them unknowingly cooperating to get the job done in our ancestors' environment.

Would you trade the many fragments of your purpose -- curiosity, love, empathy, aesthetic taste, sex drive, ambition -- for a single-minded drive to maximize the number of copies of your genes? You wouldn't, because the fragmented purposes are already hardwired into you as precious values.

Your real purposes are represented in the physical structure of your brain, in its haphazardly optimized design. If Natural Selection had been a more effective optimizer, then we would all agree that donating food to charity is even more foolish than throwing it in the trash, because the recipients would perpetuate their genes in competition with yours, without reciprocating the favor of free food. But instead, that action is universally acknowledged as a noble one, and we wouldn't have it any other way.

It's ironic that, not only do we fail to consciously represent our creator's purpose, we also fail to consciously represent a coherent picture of our own fragmented purposes. We typically act like confused servants to a crowd of waxing and waning drives. If you understand this state of affairs, then you can use the full power of conscious thought and achieve your true purposes better than you otherwise would have. You can strive to be a knowledgeable and effective servant to a crowd of waxing and waning drives.

5 comments:

anonymous said...

You suffer from the same flaw as that of the pre-Darwinian philosophers that you castigate.

"But instead, that action [donating food to a food bank] is universally acknowledged as a noble one, and we wouldn't have it any other way."

The existence of supernatural beings was once universally acknowledged.

Furthermore, you have totally misunderstood the purpose of "curiosity, love, empathy, aesthetic taste, sex drive, ambition". These qualities are all determined to get you to reproduce your genes more.

However, your most egregious error is to take the worst weakness of humans to an extreme: the desire to explain. We, as humans - the great explainers - too often miss a larger point: not everything has a purpose.

Humans, too, have no purpose. For we are no different from your pile of rocks. We, like a pile of rocks, are merely made up of interacting atoms (or quarks and leptons, if you want go subatomic).

There is no purpose to rocks. There is no purpose to humanity. There is no purpose to the universe.

Liron Shapira said...

Bob, sure you can just say "humans have no purpose" and leave it at that, and you wouldn't be wrong.

But you can also go further, and attempt to answer the question of why so many of us feel the question within us. It's not really enough to point out that the question is a wrong one. The question only goes away when you can explain the details of the cognitive algorithm that generated the question.

Boris Kazachenko said...
This comment has been removed by the author.
Boris Kazachenko said...

Evolution is not an identifiable "creator" structure,that would be an ecosystem. Since we outlasted our ecosystem, your purpose is simply your generalized motivation. As you pointed out, reproducing your genes is not it. Otherwise you would be manufacturing them by the ton via PCR. Human motivation is mostly conditioned, not inherited. A common denominator of conditioned motives is their instrumental value to prior motives. So, the "value drift" is toward more general instruments, & none is more general than cognition. I have more on that in the "Cognition" part of my "Meta Evolution" knol: http://knol.google.com/k/meta-evolution-fitness-beyond-reproduction#

jennifer said...

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Purpose in Life Essay