Preceded by: There just has to be something more, you know? Followed by: Physicalism: consciousness as the last sense.

Contents: 1. An epistemic difficulty 2. How and why to be a materialist

An epistemic difficulty

Like many readers of this blog, I am a materialist. Like many still, I was not always. Long ago, the now-rhetorical ponderings in the preceding post in fact delivered the fatal blow to my nagging suspicion that somehow, materialism just isn't enough.

By materialism, I mean the belief that the world and people are composed entirely of something called matter (a.k.a. energy), which physics currently best understands as consisting of particles (a.k.a. waves). If physics reformulates these notions, materialism can adjust with it, leading some to prefer the term "physicalism".

Now, I encounter people all the time who, because of education or disillusionment, have abandoned most aspects of religion, yet still believe in more than one than one kind of reality. It's often called "being spiritual". People often think it feels better than the alternative (see Joy in the merely real), but it also persists for what people experience as an epistemic concern:

The inability to reconcile the "experiencing self" concept with one's notion of physical reality.

This is among the the most common epistemic discomforts with materialism (I only say "discomfort", because a blank spot on your map does not correspond to a blank territory). The inside view — introspection — shows us something people call a "mind" or "spirit", and the outside view — our eyes — shows us something we call a "brain", which looks nothing at all the same. But the perceived distance between these concepts signals that connecting them would be extremely meaningful, the way superficially unrelated hypotheses and conclusions make for a very powerful theorem. For the connection to start making sense, one must realize that "you are made of matter" is as much a statement about matter as a statment about you…

The two insights of materialism: That the reconciliation of mind and matter –

is not misinformation about mind, but extra information about matter, and
is not misinformation about matter, but extra information about mind.

These are really two insights, and underusing one of them leaves a sense of "doesn't quite capture it" in the psyche. See, the way most people think or learn about physics, a particle is a tiny dot, with some attributes like charge specified by numbers, obeying certain laws of motion. But in fact, this is a model of a particle. As a conviction, physics need not claim that "dots and waves are all there is", but rather, that all there is can be described on analogy with dots and waves. Science is about modelling — a map that matches the territory — and "truth" is just how well it matches up.

And given modern science, there is something more you can say about a particle besides the geometry and equations that describe it, something which connects it to the direct, cogito-ergo-sum style knowledge we all enjoy: whatever it is, a particle is a one thousand-trillion-trillionth of a you. Yes, you, in your entirety. If part of that includes something you call a "soul", then yes, science can now model the quantitative aspects, in more or less complete detail, of a one thousand-trillion-trillionth of a "soul". Is that too much? Too incredible? A song by The Books that I like almost says it perfectly:

You are something that the whole world is made of.

This moots the debate. The first step is not to "reduce" the introspective view to the extrospective view, but to realize that they're looking at the same object. The assertion is not that "mind is just particles", but rather that "a tiny fraction of a mind" and "a tiny fraction of matter" happen to refer to the same object, and we should agree to call that object "particle". Depending on how you use the word "conscious", this does not necessarily say that a particle is conscious in the way that you are; an octant of a sphere is not a sphere. But assembled correctly, it is certainly one-eighth of a sphere!

I've learned that some people call this view "neutral monism", but I prefer to still call it materialism as an emphasis that the extrospective view "science" really has a larger quantity of information at this point in human history. This is different information about reality than provided by introspection, and to ignore it is detrimental to one's world view!

So, to help non-materialists in attaining this reconciliation of mind and matter, I've written the following rough path of ideas that one can follow:

How and why to be a materialist

Accepting materialism is saying "the rest of the world is made of whatever I am", not just "I am made of whatever the rest of the world is". And why not? In the eyes of science, these are both the same, true statement. Semantically, the first one tells you something qualitative about matter, and the second one tells you something extremely quantitative about your mind! It means modern neuroscience and biology can be used to help you understand yourself. Awesome!
Accepting physics is accepting that your "spirit" might consist of parts which, sufficiently divided and removed from context, might behave in a regular fashion. Then you might as well call the parts "particles" and call your spirit "brain", and look at all the amazing data we have about them that help describe how you work.
Beware of the works-how-it-feels bias, the fallacious additional assumption that the world works the way you feel about it. (See How an algorithm feels from the inside.) These pieces of your mind/spirit called particles are extremely tiny; in order of magnitude, they are more than twice as small as your deepest introspection, so you can't judge them very well based on instinct (a neuron is about a 10¹¹th of your mind, and an atom is about a 10¹⁴th of a neuron). And because they're so tiny and numerous, they can be put together to form things vastly different from yourself in form and function, like plants and stars.
Your instinct that the laws of physics don't fully describe you is correct! You are the way you are because of two things:
- the laws that describe your soul-pieces or particles, whatever those laws may be, and
- the way they're put together,
and the latter is almost unimaginably more significant! One way to see this is to look around at all the things that are not you. Saying how the tiny bits of your soul behave independently does not describe how to put them together, just like describing an octant of a sphere doesn't explain say how to turn eight of them into a whole sphere. Plus, even after your initial construction as a baby, a whole lot of growth and experience has configured what you are today.

Only to put this into perspective, consider that the all the most fundamental laws of physics know can certainly be written down, without evidence or much explanation, in a text file of less than 1 megabyte. The information content of the human genome, which so far seems necessary to construct a sustainable brain, is about 640 MB (efficiently encoded, that's 1.7 bits per nucleotide pair). Don't be fooled at how "small" 640 is: it means the number of possible states of that data is at least 8⁶⁴⁰ times larger than the number of the states of our text file describing all of physics! Next, the brain itself stores information as you develop, with a capacity of at least 1 terrabyte by the most conservative estimates, which means it has at least around 8¹⁵⁰⁰ times the number of possible states of the DNA sequence that first built it.

So being a desk is different from being a human, not because it's made of different stuff, but because the stuff is put together extremely differently, more differently than we can fully imagine. When people say form determines function, they should say FORM in BIG CAPITAL LETTERS. No wonder you thought particle physics "just doesn't seem to capture it"!
Your perceived distance between the concepts of "mind" and "particles" is also correct! As JanetK says, "There is no shortcut from electrons to thoughts". Continuing the connection/theorem analogy, a theorem with superficially unrelated hypotheses and conclusions is not only liable to be very useful, but to have a difficult proof as well. The analogue of the difficult proof is that, distinct from the discovery of particles themselves, massive amounts of technological progress and research have been required to establish the connection between:
- how particles work and how you look from the outside (neurochemistry/neurobiology), and
- how you look from the outside and how you look from the inside (neuropsychology).
Indeed, the perceptual distance between the second pair is why people use the concepts "brain" and "mind" separately: "brain" is a model for the outside view, and "mind" is a model for the inside view. The analogue of the theorem's usefulness is how much neurology can say and do about our minds:
- treat mental illness,
- restore lost memories,
- design brain surgery,
- explain cognitive biases,
- physically relate our emotions to each other…
Adjusting emotionally is extremely important as you bring materialism under consideration, not only to accomodate changing your beliefs, but to cope with them when they do change. You may need to redescribe morality, what makes you happy, and why you want to be alive, but none of these things needs to be revoked, and LessWrong is by far the best community I've ever seen to help with this transition. For example, Eliezer has written a chronological account of his Coming of Age as a rationalist, and he has certainly maintained a sense of morality and life-worth. I recommend building an appropriate emotional safety net while you consider materialism, not just to combat the bias of fear, but so you're ready when one day you realize oh my gosh I'm a materialist!

I have a friend who says that instead of classifying people as believing in the material or the supernatural, he classifies them by whether they think more than one of those things exists and are different. Roughly speaking, dualists and non-dualists. I think he's got the right idea. Why bother believing in more than one kind of thing? Why believe in separate "soul" and "material" if the world can just as well be made of tiny specks of regularly-behaved "spirit"? It's the same theory, and watching out for works-how-it-feels bias, you gain a lot of tangible insight about yourself if you realize they're the same.

So do what's right. Right for you, right for your loved ones, and right for rightness itself if that matters to you. You probably already know what it means to be a good person, and your good intentions just won't work if you use poor judgement. Start thinking about materialism so you can know more, and make better, well-informed decisions.

Who believes in the supernatural is simply underestimating the natural.

There is no something more, because there is no something less… but there certainly and most definitely is you.

Follow up to comments:

One can only get so far from dualism in a single sitting, and what this article includes is a much a function of my time as of its validity. For now I'll leave it up to others to argue stronger positions than those presented here, but to acknowledge, some important issues I did not address include:

Whatever stuff or process the world comprises, is it merely accessible to physics, or can physics describe its nature entirely? And supposing it can, is consciousness an entirely mathematical phenomenon that is unaffected by how it is physically implemented? That is, if we made a neural network computationally isomorphic to the human brain, but in a different physical arrangement (e.g. a silicon based computer), should you be as certain of its consciousness as of the consciousness of other humans? And more questions...

A rough outline of some stances on the questions above is as follows: (to avoid debate I'll omit the term naturalism, though I do approve of its normative use)

Monism: the world comprises just one genre of stuff or process (no natural/supernatural distinction).

This article: this stuff or process is physically accessible, and is therefore amenable to study by the natural sciences.

Physicalism: the stuff or process is no more extensive than its description in terms of physics.

Computationalism: consciousness is a mathematical phenomenon, unaffected by how it is physically represented or implemented.

And of course it is also important to question whether these distinctions are practical, meaningful, or merely illusory. It all needs to be cleaned and carefully disected. Have at it, LessWrong!