This is a special post for quick takes by David Gross. Only they can create top-level comments. Comments here also appear on the Quick Takes page and All Posts page.
17 comments, sorted by Click to highlight new comments since:

This is a brief follow-up to my post “Redirecting one’s own taxes as an effective altruism method.” Since I wrote that post:

  1. Scott Alexander boosted (not to be interpreted as endorsed) my post on Astral Codex Ten, which helped to give it more than typical reach.
  2. In a flinchy spasm of post-SBF timidity, GiveWell explicitly told me they did not want to get their hands dirty with my donations of redirected taxes any more.
  3. My tax arrears for 2013 ($5,932 original tax + ~$5,467 in interest & penalties) were annulled by the statute of limitations.
  4. I made a $5,932 donation to Charity Entrepreneurship to celebrate.

In my fantasies, if I ever were to get that god-like glimpse at how everything actually is, with all that is currently hidden unveiled, it would be something like the feeling you have when you get a joke, or see a "magic eye" illustration, or understand an illusionist's trick, or learn to juggle: what was formerly perplexing and incoherent becomes in a snap simple and integrated, and there's a relieving feeling of "ah, but of course."

But it lately occurs to me that the things I have wrong about the world are probably things I've grasped at exactly because they are more simple and more integrated than the reality they hope to approximate. I think if I really were to get this god-like glimpse, I wouldn't know what to do with it. I probably couldn't fit it in with anything I think I know. It wouldn't mesh. It wouldn't be the missing piece of my puzzle, but would overturn the table the incomplete puzzle is on. I have a feeling I couldn't even be there, intact, in the way I am now: observing, puzzling over things, trying to shuffle and combine ideas. What makes me think I can bring my face along, face-to-face with the All?

And then today I read this: “We yearn for the transcendent, for God, for something divine and good and pure, but in picturing the transcendent we transform it into idols which we then realize to be contingent particulars, just things among others here below. If we destroy these idols in order to reach something untainted and pure, what we really need, the thing itself, we render the Divine ineffable, and as such in peril of being judged non-existent. Then the sense of the Divine vanishes in the attempt to preserve it.” (Iris Murdoch, Metaphysics as a Guide to Morals)

I like to phrase it as "the path to simplicity involves a lot of detours." Yes, Newtonian mechanics doesn't account for the orbit of Mercury but it turned out there was an even simpler, more parsimonious theory, general relativity, waiting for us.

  1. We inhabit this real material world, the one which we perceive all around us (and which somehow gives rise to perceptive and self-conscious beings like us).
  2. Though not all of our perceptions conform to a real material world. We may be fooled by things like illusions or hallucinations or dreams that mimic perceptions of this world but are actually all in our minds.
  3. Indeed if you examine your perceptions closely, you'll see that none of them actually give you representations of the material world, but merely reactions to it.
  4. In fact, since the only evidence we have is of perceptions, the "material world" is more of a metaphysical hypothesis we use to explain patterns in our perceptions, not something we can vouch for as actually existing.
  5. Since this hypothesis is untestable, it is best put aside when we consider what actually exists. The "material world" is not a thing, but a framework and vocabulary useful for discussing regularities in what is really real.
  6. What is really "real" -- what the word "real" means -- is our moment to moment perceptions and interpretations, which appear to us in the form of a material world that we inhabit. 
  7. GOTO 1

How to best break out of this loop?

In (3), the word “merely” is doing a lot of unexamined work. My perceptions have a coherence to them, an obstinate coherence that I cannot wish away. I reach out for the coffee cup that I see, and it shows up to my sense of touch. What does it mean to call this a “mere” response, when it maintains a persistent similarity of structure to my idea of what is out there—that is, it is a representation of it.

In (4), if the hypothesis explains the perceptions, the perceptions are evidence for the hypothesis. These are two different ways of saying the same thing.

A hypothesis that explains the perceptions can be a just-so story. For any set of perceptions ζ, there may be a vast number of hypotheses that explain those perceptions. How do you choose among them?

In other words, if f() and g() both explain ζ equally well, but are incompatible in all sorts of other ways for which you do not have perceptions to distinguish them, ζ may be "evidence for the hypothesis" f and ζ may be "evidence for the hypothesis" g, but ζ offers no help in determining whether f or g is truer. Consider e.g. f is idealism, g is realism, or some other incompatible metaphysical positions that start with our perceptions and speculate from there.

An author I read recently compared this obstinate coherence of our perceptions to a GUI. When I move my mouse pointer to a file, click, and drag that file into another folder, I'm doing something that has predictable results, and that is similar to other actions I've performed in the past, and that plays nicely with my intuitions about objects and motion and so forth. But it would be a mistake for me to then extrapolate from this and assume that somewhere on my hard drive or in my computer memory is a "file" which I have "dragged" "into" a "folder". My perceptions via the interface may have consistency and practical utility, but they are not themselves a reliable guide to the actual state of the world.

Obstinate coherence and persistent similarity of structure are intriguing but they are limited in how much they can explain by themselves.

Dragging files around in a GUI is a familiar action that does known things with known consequences. Somewhere on the hard disc (or SSD, or somewhere in the cloud, etc.) there is indeed a "file" which has indeed been "moved" into a "folder", and taking off those quotation marks only requires some background knowledge (which in fact I have) of the lower-level things that are going on and which the GUI presents to me through this visual metaphor.

Some explanations work better than others. The idea that there is stuff out there that gives rise to my perceptions, and which I can act on with predictable results, seems to me the obvious explanation that any other contender will have to do a great deal of work to topple from the plinth. The various philosophical arguments over doctrines such as "idealism", "realism", and so on are more like a musical recreation (see my other comment) than anything to take seriously as a search for truth. They are hardly the sort of thing that can be right or wrong, and to the extent that they are, they are all wrong.

Ok, that's my personal view of a lot of philosophy, but I'm not the only one.

It sounds like you want to say things like "coherence and persistent similarity of structure in perceptions demonstrates that perceptions are representations of things external to the perceptions themselves" or "the idea that there is stuff out there seems the obvious explanation" or "explanations that work better than others are the best alternatives in the search for truth" and yet you also want to say "pish, philosophy is rubbish; I don't need to defend an opinion about realism or idealism or any of that nonsense". In fact what you're doing isn't some alternative to philosophy, but a variety of it.

Some philosophy is rubbish. Quite a lot, I believe. And with a statement such as "perceptions are caused by things external to the perceptions themselves", which I find unremarkable in itself as a prima facie obvious hypothesis to run with, there is a tendency for philosophers to go off the rails immediately by inventing precise definitions of words such as "perceptions", "are", and "caused", and elaborating all manner of quibbles and paradoxes. Hence the whole tedious catalogue of realisms.

Science did not get anywhere by speculating on whether there are four or five elements and arguing about their natures.


There's a soft patch around 5 and 6. Why is testability important? It's a charactersitic of science, but science assumes an external world. It's not a characteristic of philosophy -- good explanation is enough in philosophy, and the general posit of some sort of external world does explanatory work. And it's separate from the specific posit that the external world is knowable in some particular way.

It's a characteristic of philosophy, too, at least according to the positivists. If you're humoring a metaphysical theory that could not even in theory be confirmed or falsified by some possible observation, they suggest that you're really engaging in mythmaking or poetry or something, not philosophy.


Positivism isn't necessarily true, and if it is, it still doesn't get you to 6, because LP recommends you have no metaphysics which would imply no solipsistic metaphysics. (LP might be compatible with the claim that your own sense-data are all you can know , but that isn't quite the same thing).

A lot of philosophy is like that. Or perhaps it is better compared to music. Music sounds meaningful, but no-one has explained what it means. Even so, much philosophy sounds meaningful, consisting of grammatical sentences with a sense of coherence, but actually meaning nothing. This is why there is no progress in philosophy, any more than there is in music. New forms can be invented and other forms can go out of fashion, but the only development is the ever-greater sprawl of the forest.

According to Seigen Ishin (Ch'ing-yüan Wei-hsin):

"Before a man studies Zen, to him mountains are mountains and waters are waters; after he gets an insight into the truth of Zen through the instruction of a good master, mountains to him are not mountains and waters are not waters; but after this when he really attains to the abode of rest, mountains are once more mountains and waters are waters."

(D. T. Suzuki, Essays in Zen Buddhism, First Series, 1926, London; New York: Published for the Buddhist Society, London by Rider, p. 24.)

What loop? They are all various viewpoints on the nature of reality, not steps you have to go through in some order or anything. (1) is a more useful viewpoint than the rest, and you can adopt that one for 99%+ of everything you think about and only care about the rest as basically ideas to toy with rather than live by.

I don't know about you (assuming you even exist in any sense other than my perception of words on a screen), but to me a model that an external reality exists beyond what I can perceive is amazingly useful for essentially everything. Even if it might not be actually true, it explains my perceptions to a degree that seems incredible if it were not even partly true. Even most of the apparent exceptions in (2) are well explained by it once your physical model includes much of how perception works.

So while (4) holds, it's to such a powerful degree that (2) to (6) are essentially identical to (1).

Put your phone in the oven and stand in the grass and eat some grass and see how it tastes