# April 2019: Back to the rough ground!

We have got on to slippery ice where there is no friction, and so, in a certain sense, the conditions are ideal; but also, just because of that, we are unable to walk. We want to walk: so we need friction. Back to the rough ground!

Wittgenstein, Philosophical Investigations, I.107

… I would nevertheless like to try to imagine a world in which it was natural to think that 2+2=5 and see what that tells us about our belief that 2+2=4.

In such a world, physical objects might have less clear boundaries than they do in ours, or vary more over time, and the following might be an observed empirical fact: that if you put two objects into a container, and then another two, and if you then look inside the container, you will find not four objects but five. A phenomenon like that, though strange, is certainly not a logical impossibility, though one does feel the need for more details: for example, if a being in this world holds up two fingers on one hand and two on the other, how many fingers is it holding up? If you put no apples into a bag and then put no further apples into the bag, do you have one apple? But then why not a tomato?

Timothy Gowers, Does mathematics need a philosophy?

OK, there are two quotes this time, and one is by Wittgenstein, so you can tell that this one is going to be extra pretentious. (It’s also long, though a lot of it is quoting other people – I’ve got a even worse case of blockquoteitis than normal.) I’ve been reading sections of Philosophical Investigations, in a fairly unsystematic way, along with some other relevant bits and pieces like the Gowers talk quoted above, and I’m going to talk about a few things I’ve noticed.

I’ll also talk about Anki, and some thoughts on last month’s internet diet. It went very well again – I escaped my normal reading loops and found a lot of new things (I’ll finish this newsletter off with a partial list). Last year’s one also went very well, so at this point I have to seriously think about making a permanent change.

I’m not that bothered about wasting time, exactly. I’m happy enough with the amount I get done, and I’d struggle to do much more and keep up a full time job. It’s more that the internet wastes my time twice. Once while I’m actually reading the stuff – this is the one I don’t really care about – and a second time when I’m, say, walking to work, the ideal time for having some interesting thoughts, and all I have is leftover brain noise from some random drama I was reading the previous evening. This month my head wasn’t crammed full of other people’s internet noise, so there was more space to fill it with some thoughts of my own.

On the other hand… I definitely don’t want to give up Twitter and blogs completely. When I do these diets they feel good, but also like I’m missing out on something genuinely valuable. I don’t think this is just fooling myself, either, because when I gave up Tumblr it was very obviously a great decision, and my thought process was more like ‘why didn’t I give up this crap ages ago?’, and after a few weeks I didn’t even miss it. There are some major differences:

• The big one is that I’m much more plugged in to an actual community of people I like. Tumblr was my first time commenting on the internet at all rather than just lurking, and I had a few nice interactions there, but mostly only hung around the edges muttering to myself. Now I write a blog that I take seriously rather than treating it as a throwaway joke, and I risk having actual opinions under my real name, getting into discussions, etc. I’ve had a few long email conversations, met several people for real, had my ideas developed through lots of thoughtful comments and had up all kinds of useful links and references sent my way. It’s become an important part of my life and I really miss people when I do these internet diets.
• The tone is a lot better. In my tiny bit of Twitter, I mean, not general Twitter which is a cesspit of politics ranting. Rat-adjacent tumblr has some really vivid personalities, and some fantastically distinctive writing voices, and I miss that side of it a little bit. But in general… people don’t end up on that part of Tumblr because they’re thrilled with how their lives are currently going. It’s a lot of unhappy people interacting with differently unhappy people and getting into arguments. Now I’m in some magical part of the internet where people are actually nice to each other most of the time, and enthusiastic about whatever they’ve been learning.
• I am learning some new things. Scott Alexander once jokingly drew up an Official Rationalist Tumblr Argument Schedule, which hit a bit too close to the mark. It really was like that absolutely all the time. It was entertainingly new bullshit to me when I first discovered it in 2014, but the same bullshit cycles round again and again and the novelty wears off quickly.

I’m not sure what I want to do long term, and I don’t necessarily always want to be doing the same thing. If I’m writing blog posts it seems to be useful to immerse myself in the stream more, whereas if for physics it’s useful to get out of it (or maybe get a more physics-y stream than the one I’ve been in recently). For now I’ll keep fiddling around with various monthly experiments and see what happens. I want to concentrate on physics over the summer, so I’ll lean towards getting out of the stream. This month I will be on Twitter and blogs on Thursdays and Fridays, and off the other days. (Also I’ll be on there today.)

I don’t know how well that’ll work. A few years ago I tried only being allowed on within certain hours, and I absolutely hated that – I had to keep imposing the rule, so it actually felt much more constraining and annoying than giving everything up completely. It was also not very effective, because I was still filling my head with my normal bullshit on a daily timescale. I think 2 days on, 5 days off is a different enough timescale that it’ll have different dynamics. But I might still hate it, who knows.

# Wittgenstein

I had Philosophical Investigations out of the library for about a year and could never be bothered to read it. Then it got recalled, so of course I suddenly really wanted to. So I got another copy out of a different library, and will probably buy it.

I keep just opening the book somewhere in the first half and reading a few sections at a time, rather than trying to work through it in a linear way. Maybe I should be more systematic, but I’m still picking up a few things. I’d sort of absorbed some of the ideas from secondary sources – language games, family resemblances – but this got me a bit further.

The rest of this is also not going to be systematic – just comments on what I read.

## Overlapping of many fibres

And we extend our concept of number, as in spinning a thread we twist fibre on fibre. And the strength of the thread resides not in the fact that some one fibre runs through its whole length, but in the overlapping of many fibres.

This is from section 67. Sarah Perry explains the spinning analogy, with pictures of actual yarn, in “Something Runs Through The Whole Thread”

I realised that this is also how the whole book works! The numbered sections are the fibres, and the strength of the argument is in how the sections overlap, rather than a single thread of argument running along the whole book. This must be a common observation. In fact, Wittgenstein says something similar in the Preface:

I have written down all these thoughts as remarks, short paragraphs, sometimes in longer chains about the same subject, sometimes jumping, in a sudden change, from one area to another. Originally it was my intention to bring all this together in a book whose form I thought of differently at different times. But it seemed to me essential that in the book the thoughts should proceed from one subject to another in a natural, smooth sequence.

After several unsuccessful attempts to weld my results together into such a whole, I realized that I should never succeed. The best that I could write would never be more than philosophical remarks; my thoughts soon grew feeble if I tried to force them along a single track against their natural inclination. And this was, of course, connected with the very nature of the investigation. For it compels us to travel criss-cross in every direction over a wide field of thought.

But it’s something that I noticed myself, before I went back and read the Preface.

I like the style it actually feels less fake than normal writing, rather than a weird affectation. Normally when I’m writing I produce a lot of short sections and then fake up a linear argument by inserting bits of ‘and therefore’ connective tissue between them. Just doing away with the connections altogether is quite appealing.

I also remembered this C. S. Lewis quotation:

You may have noticed that the books you really love are bound together by a secret thread. You know very well what is the common quality that makes you love them, though you cannot put it into words: but most of your friends do not see it at all, and often wonder why, liking this, you should also like that. Again, you have stood before some landscape, which seems to embody what you have been looking for all your life; and then turned to the friend at your side who appears to be seeing what you saw but at the first words a gulf yawns between you, and you realise that this landscape means something totally different to him, that he is pursuing an alien vision and cares nothing for the ineffable suggestion by which you are transported. Even in your hobbies, has there not always been some secret attraction which the others are curiously ignorant of something, not to be identified with, but always on the verge of breaking through, the smell of cut wood in the workshop or the clap-clap of water against the boat’s side?

This feels very true to me. But I don’t buy the next part of Lewis’s version, the bit where this comes from some deep resonance from your true self, “the secret signature of each soul”:

Are not all lifelong friendships born at the moment when at last you meet another human being who has some inkling (but faint and uncertain even in the best) of that something which you were born desiring, and which, beneath the flux of other desires and in all the momentary silences between the louder passions, night and day, year by year, from childhood to old age, you are looking for, watching for, listening for? You have never had it. All the things that have ever deeply possessed your soul have been but hints of it tantalising glimpses, promises never quite fulfilled, echoes that died away just as they caught your ear. But if it should really become manifest if there ever came an echo that did not die away but swelled into the sound itself you would know it. Beyond all possibility of doubt you would say “Here at last is the thing I was made for”. We cannot tell each other about it. It is the secret signature of each soul, the incommunicable and unappeasable want, the thing we desired before we met our wives or made our friends or chose our work, and which we shall still desire on our deathbeds, when the mind no longer knows wife or friend or work. While we are, this is. If we lose this, we lose all.

If you instead follow Wittgenstein, and make the secret thread a literal thread of many overlapping fibres drawn from past experience, you get something that’s maybe less poetic but makes a whole lot more sense.

## Vagueness

I hadn’t realised how good Wittgenstein was on vagueness. There are lots of great sections I could quote on how some things are inherently vague, but I’ll just pick one (from section 77):

… imagine having to draw a sharp picture ‘corresponding’ to a blurred one. In the latter there is a blurred red rectangle; you replace it with a sharp one. Of course — several such sharply delineated rectangles could be drawn to correspond to the blurred one. — But if the colours in the original shade into one another without a hint of any boundary, won’t it become a hopeless task to draw a sharp picture corresponding to the blurred one? Won’t you then have to say: “Here I might just as well draw a circle as a rectangle or a heart, for all the colours merge. Anything — and nothing — is right.” —— And this is the position in which, for example, someone finds himself in ethics or aesthetics when he looks for definitions that correspond to our concepts.

## Gowers on Wittgenstein

I had an idea that Timothy Gowers had written something where he talked about the later Wittgenstein, and it turned out to be his talk on Does mathematics need a philosophy? He very briefly (and mostly unenthusiastically) discusses the classic options of formalism, logicism and Platonism. Then we get on to the Wittgenstein connection:

… let me give you a very quick idea of where my own philosophical sympathies lie.

I take the view, which I learnt recently goes under the name of naturalism, that a proper philosophical account of mathematics should be grounded in the actual practice of mathematicians. In fact, I should confess that I am a fan of the later Wittgenstein, and I broadly agree with his statement that “the meaning of a word is its use in the language”. … So my general approach to a philosophical question in mathematics is to ask myself how a typical mathematician would react to it, and why.

There are some interesting examples, including the ‘2+2=5’ one quoted at the start. I like the one on ordered pairs. First he gives a couple of ways of thinking about them. There’s the standard mathematical definition, and the more informal way that they are normally first encountered:

Let x and y be two mathematical objects. Then from a formal point of view the ordered pair (x,y) is defined to be the set {{x},{x,y}}, and it can be checked easily that

{{x},{x,y}}={{z},{z,w}} if and only if x=z and y=w.

Less formally, the ordered pair (x,y) is a bit like the set {x,y} except that “the order matters” and x is allowed to equal y.

Contrast this account with the way ordered pairs are sneaked in at a school level. There, the phrase “ordered pair” is not even used. Instead, schoolchildren are told that points in the plane can be represented by coordinates, and that the point (x,y) means the point x to the right and y up from the origin. It is then geometrically obvious that (x,y)=(z,w) if and only if x=z and y=w.

The ‘school level’ version works fine in practice: ‘because of their experience with plane geometry, they will take for granted that (x,y)=(z,w) if and only if x=z and y=w, whether or not you bother to spell this out as an axiom for ordered pairs.’ So why bother with the formal version? The main point seems to be consistency:

… if you want to adopt a statement such as

(x,y)=(z,w) if and only if x=y and z=w

as an axiom, then you are obliged to show that your axiom is consistent. And this you do by constructing a model that satisfies the axiom. For ordered pairs, the strange-looking definition (x,y)={{x},{x,y}} is exactly such a model. What this shows is that ordered pairs can be defined in terms of sets and the axiom for ordered pairs can then be deduced from the axioms of set theory. So we are not making new ontological commitments by introducing ordered pairs, or being asked to accept any new and unproved mathematical beliefs.

But other models would also do the job. The exact translation of our intuitive idea of an ordered pair into set theory is somewhat arbitrary. What matters about ordered pairs is mainly just how we use them.

I don’t think there is, at least if you want to start your explanation with the words, “An ordered pair is”. At least, I have never found a completely satisfactory way of defining them in lectures. To my mind this presents a pretty serious difficulty for Platonism. And yet, as I have said, it doesn’t really seem to matter to mathematics. Why not?

I would contend that it doesn’t matter because it never matters what a mathematical object is, or whether it exists. What does matter is the set of rules governing how you talk about it – or perhaps I should say, since that sounds as though “it” refers to something, what matters about a piece of mathematical terminology is the set of rules governing its use. In the case of ordered pairs, there is only one rule that matters – the one I have mentioned several times that tells us when two of them are equal.

This leads him to a rather subtle kind of formalism:

I also believe that the formalist way of looking at mathematics has beneficial pedagogical consequences. If you are too much of a Platonist or logicist, you may well be tempted by the idea that an ordered pair is really a funny kind of set – the idea I criticized earlier. And if you teach that to undergraduates, you will confuse them unnecessarily. The same goes for many artificial definitions. What matters about them is the basic properties enjoyed by the objects being defined, and learning to use these fluently and easily means learning appropriate replacement rules rather than grasping the essence of the concept. If you take this attitude to the kind of basic undergraduate mathematics I am teaching this term, you find that many proofs write themselves – an assertion I could back up with several examples.

I’m not sure what I think of this yet. I definitely always have this strong urge to understand what some piece of mathematics is really about, in some badly defined ontological way – I do want to ‘grasp the essence of the concept’ – and there’s something very aesthetically unpleasant about formalism. I’m not convinced that Gowers’s type of formalism is really all that formalist, though – after all, the property of the equality of ordered pairs is grounded in our pretheoretic understanding of coordinates in a plane. And I’m also not convinced that my ‘what does it really mean’ obsession is very helpful or productive, either, though it does really pay off occasionally.

Finally, I enjoyed his politely phrased bit of snarking about philosophy of mathematics at the end:

Suppose a paper were published tomorrow that gave a new and very compelling argument for some position in the philosophy of mathematics, and that, most unusually, the argument caused many philosophers to abandon their old beliefs and embrace a whole new -ism. What would be the effect on mathematics? I contend that there would be almost none, that the development would go virtually unnoticed. And basically, the reason is that the questions considered fundamental by philosophers are the strange, external ones that seem to make no difference to the real, internal business of doing mathematics. I can’t resist quoting Wittgenstein here:

> A wheel that can be turned though nothing else moves with it, is not part of the mechanism.

Now this is not a wholly fair comment about philosophers of mathematics, since much of what they do is of a technical nature – attempting to reduce one sort of discourse to another, investigating complicated logical systems and so on. This may not be of much relevance to mathematicians, but neither are some branches of mathematics relevant to other ones. That does not make them unrespectable.

But the point remains that if A is a mathematician who believes that mathematical objects exist in a Platonic sense, his outward behaviour will be no different from that of his colleague B who believes that they are fictitious entities, and hers in turn will be just like that of C who believes that the very question of whether they exist is meaningless.

## Knowing How and Knowing That

I also read Gilbert Ryle’s Knowing How and Knowing That. This paper is short and pretty easy going (Ryle’s style is to pile up lots of everyday examples) and covers some similar ground. He’s attacking the idea that intelligent action involves first knowing some things, in the form of explicit propositions, and then applying them:

The prevailing doctrine … holds: (1) that Intelligence is a special faculty, the exercises of which are those specific internal acts which are called acts of thinking, namely, the operations of considering propositions ; (2) that practical activities merit their titles “intelligent”, “clever”, and the rest only because they are accompanied by some internal acts of considering propositions…. That is to say, doing things is never itself an exercise of intelligence, but is, at best, a process introduced and somehow steered by some ulterior act of theorising.

To explain how thinking affects the course of practice, one or more go-between faculties are postulated which are, by definition, incapable of considering regulative propositions, yet are, by definition, competent correctly to execute them.

Instead, he argues that action can be intelligent even if no propositions are explicitly considered – you can have knowledge-how without knowledge that:

In opposition to this doctrine, I try to show that intelligence is directly exercised as well in some practical performances as in some theoretical performances and that an intelligent performance need incorporate no “shadow-act” of contemplating regulative propositions.

… Intelligently to do something (whether internally or externally) is not to do two things, one “in our heads” and the other perhaps in the outside world; it is to do one thing in a certain manner. It is somewhat like dancing gracefully, which differs from St. Vitus’ dance, not by its incorporations of any extra motions (internal or external) but by the way in which the motions are executed.

In fact, he goes on to argue that ’knowledge-how is a concept logically prior to the concept of knowledge-that.’ For example, take a clever chess player and a stupid one:

We can imagine a clever player generously imparting to his stupid opponent so many rules, tactical maxims, “wrinkles”, etc., that he could think of no more to tell him; his opponent might accept and memorise all of them, and be able and ready to recite them correctly on demand. Yet he might still play chess stupidly, that is, be unable intelligently to apply the maxims, etc.

You could argue the stupid player’s behaviour is caused by not really knowing the propositions that the clever player has provided. If he could bring them to mind at the point where they were useful, he would do the right thing.

But, unfortunately, if he was stupid (a) he would be unlikely to tell himself the appropriate maxim at the moment when it was needed and (b) even if by luck this maxim did occur to him at the moment when it was needed, he might be too stupid to follow it.

So we’ve got ourselves into something like the frame problem… the stupid player needs more propositions to tell him when and how to apply the propositions the clever player has taught him, and then presumably more propositions to apply those, and so on in an infinite regress. This can be avoided by denying that the difference between the players is that the clever player’s success comes through knowing propositions that the stupid player doesn’t. The rest of the paper goes through this in some more detail, with more examples, but this seems to be the key point.

## Slippery ice

The Wittgenstein quote I used at the start of this newsletter is a very concise summary of this.  Knowing-how provides the friction, by grounding knowledge in the background of successful action. A formal theory on its own looks elegant (‘in a certain sense, the conditions are ideal’). But without an understanding of how to use it, we are unable to walk.

We want to walk: so we need friction. Back to the rough ground!

# Anki

After all this enthusiasm for knowing-how, it’s kind of weird that I currently seem to be working on improving my knowing-that. Anki tends to be quite far towards the knowing-that end. But that’s what I seem to need at the moment in a lot of places, adding some articulation and getting out of the porridgey sludge of vague understanding that learning-by-doing often gives me. Thick mud is also bad for walking.

Anki is going slowly but steadily. It took me a lot of the month to just get into the habit of using it, and I still find the process quite clunky. I’d rather review cards on my phone, but adding cards mostly has to be done in the desktop application, and then they need to be synced with a web service, and it all feels like a lot of hassle.

I quickly dialled back on the idea of working through a paper using Anki. It’s too ambitious for a first attempt at using it, and I’m better off doing anything that trains the habit of making cards at all. I’m mostly going for quite simple ‘factoid’ cards, either to do with the command line or bits of physics stuff that come up.

I still think there’s something potentially very useful there, though, which is why I’m continuing despite the hassle. It’s more in how it changes what I do outside of making the cards, rather than the cards themselves. I’ve found myself learning new things with a view to remembering the details, and it’s sharpening them up in a satisfying way.

I was learning some tasks at work from a colleague a while back, and was impressed by how much he just typed from memory. Stuff that I already saw the value of knowing, like details of various commands and the flags they take, but also real trivia like the URLs of the various database servers we have. I’d never even considered learning that sort of thing – after all, you can just look it up – but there seems to be something to it. The complete effect is a level of fluency that I just don’t get when I have to keep stopping to find these things out.

I mean, I’m not going to immediately go sit down and cram database URLs. I doubt that’s the best way to use my time. But probably he didn’t cram them either, he just stayed aware of the potential for memorisation rather than mindlessly executing instructions. I think just paying attention to things as things I’d potentially want to memorise would go a long way.

I made some notes on what I read, as it was so different to what I’d read in a normal month. Here are some of the highlights:

• I spent some time on Longform and Longreads trying to sate my craving for walls of text on the web. These sites tend to sample from the Harper’s/Atlantic/New Yorker cluster, plus some from the more serious end of the web-only sites. I used to read a fair amount of this sort of thing but haven’t in years, and it’s quite jarring going back. Partly for the particular style that that kind of American magazine writing has, which I don’t see much of now I mostly read blogs, but mostly for the pessimistic tone. As in, it’s all ‘I did a PhD in medieval French and now I have a shitty adjunct job and also write for Buzzfeed to pay the bills’, whereas my current part of the internet is more like ‘I took a first year course in linear algebra once and now Google pays me six figures, here are my opinions on consciousness based on a popular science book I read once.’ Which is just more fun, even when it’s awful.

Some of the better things I found:

• I found this set of short reviews by Jamie Brandon of a gigantic pile of papers from something called the Psychology of Programming Interest Group (PPIG). That sounds like an interesting topic area to me, but overall he was not impressed:

What did I learn?

Not a great deal about the psychology of programming itself. For the most part the field doesn’t feel like a stumbling progression towards enlightenment, but just plain stumbling.

Here are some common failure modes that frustrated me:

Plain bad science, especially in the early years where a lot of the experiments are ‘my pet project vs the world’ and somehow the pet project always comes out looking good. My favorite example has a graph where the control group are clearly performing better, and the author explains this away, saying it’s because the control group were cheating, and in the conclusion of the paper declares the treatment a success. And it was published!

Failing to validate instruments. In particular, a lot of papers that involve coding qualitative data didn’t bother to have two people code the data independently to check for agreement.

‘We have to do some science, and this is science’. Many of the experiments are from the start clearly incapable of answering the original question. I realize that getting good data for these subjects is hard, but the opportunity cost still stings. Do a different experiment!

Theoryless science. For example, one paper had programmers read programs under an eye-tracker and found there was a significant difference in the gaze patterns between the more experienced group and the less experienced group. So what? There’s no suggestions as to what it means or how it can be used or under what conditions it’s expected to be replicable. These papers typically end with “further research is required” and then no further research materializes.

There are a few promising looking ones, though, so it might be of interest to someone more patient than me. The rest of his website is also worth a look.

• I read some Remains of the Day posts. The author, Eugene Wei, is an early Amazon employee who’s worked for a string of tech companies. He’s in the same part of the internet as Dan Wang, and probably not so far from the ‘optimism Twitter’ cluster that includes Michael Nielsen and Devon Zuegel and I don’t know who else. This is close enough to my part of the internet that I wasn’t sure whether it should count as part of the ban, but I hadn’t read him before so I let it through. It’s very good. He writes loooooong posts about a lot of topics, but common themes are tech, China, and something like ‘taking pop culture seriously’ – thousands of words on sports commentary, movie stars, chain restaurant design and social posturing on Snapchat, from the point of view of someone who gives way more of a shit about all these things than the average nerd. Because I am the average nerd in this respect, I spent a while thinking ‘but why do you care so much about this junk’, but his enthusiasm won me over and I started to see what he was seeing. He’s interested in mega popular stuff that millions or billions of people like, which is naturally going to tap into human universals. This post on trash talk from The Odyssey forwards is a good example. Also as a sop to his nerd readers there is a post on graph legends in Excel

• I discovered the philosopher Eric Schwitzgebel, who has been blogging for years at The Splintered Mind and is very funny. His list of papers also has some great stuff. A couple of highlights:
• He’s done a lot of research on whether professional moral philosophers are more ethical than others, on metrics ranging from membership of the Nazi party in the 30s right down to slamming the door when coming in late to conference sessions. Generally the answer is ‘no’. (This is kind of similar to what Gowers says about philosophy of mathematics – developments in it don’t affect the actual practice of doing maths at all.) Nice summary in Aiming for Moral Mediocrity, which is an eerily good description of the level of morality that I seem to naturally manage:

Most people aim to be about as morally good as their peers, not especially better, not especially worse. We do not aim to be good, or non-bad, or to act permissibly rather than impermissibly, by fixed moral standards. Rather, we notice the typical behavior of our peers, then calibrate toward so-so. This is a somewhat bad way to be, but it’s not a terribly bad way to be.

The ‘Aiming for B+’ section feels particularly accurate:

A few years ago, I was away from my family at a luxurious ethics conference, enjoying an expensive restaurant meal, surrounded by philosophers and moral psychologists. I raised some of these issues.

“B+,” said one of the others there at the dinner with me. He was a world-renowned ethicist. “That’s what I’m aiming for. B+.”

… B+ probably isn’t low enough to be mediocre, exactly. B+ is good. It’s just not excellent. Maybe, really, instead of aiming for mediocrity, most people aim for something like B+ – a bit above mediocre, but shy of excellent?

… However, I suspect that most people who think they are aiming for B+ are in fact aiming lower. Consider the undergraduate student who tells you that they are aiming for a B+ in your class. If they’re really aiming for a B+, they should be willing to calibrate their effort accordingly. If the student would dial back their effort after getting an A and if they would increase their effort after getting a C+, then yes, it’s probably right to say that they’re aiming for a B+. If the C+ leaves them disappointed but they are unprepared to work on improving (and there are no extenuating circumstances), then it’s probably more accurate to say that they were kind of hoping that a B+ would fall into their lap, rather than really aiming for a B+.

Bizarre views are a hazard of metaphysics. The metaphysician starts, seemingly, with some highly plausible initial commitments or commonsense intuitions – that there is a prime number between 2 and 5, that I could have had eggs for breakfast, that squeezing the clay statue would destroy the statue but not the lump of clay. She thinks long and hard about what, exactly, these claims imply. In the end, she finds herself positing a realm of abstract Platonic entities, or the real existence of an infinite number of possible worlds, or a huge population of spatiotemporally coincident things on her mantelpiece.

I now know that there’s a Wittgenstein quote for that!

106. Here it is difficult to keep our heads above water, as it were, to see that we must stick to matters of everyday thought, and not to get on the wrong track where it seems that we have to describe extreme subtleties, which again we are quite unable to describe with the means at our disposal. We feel as if we had to repair a torn spider’s web with our fingers.

• The mathematics of paper marbling. There’s also an online simulation hereit’s kind of buggy and almost unusable in Chrome (worked OK in Firefox). The force field button idea is really nice though. I do not need another project right now, but I want to play with this so much 😦

Now I’ve got access to Twitter and my RSS feed again, I’ll have to see how this compares to what I would have read otherwise. I’m sure it’s better overall, but not uniformly better. It removes the absolute pits of my normal internet experience, like trawling Tumblr or Sneerclub for hours to piece together some petty rationalist drama involving a bunch of people in California that I’ve never met (why do I do this to myself?). It also slices off some of the peaks. The best writing I see in my bit of the internet is better than almost anything I read online this month, and also I have direct interaction with people on Twitter passing on interesting papers and articles that I’d never have found on my own.

A lot of what I read, especially the Longreads stuff, was kind of ‘cognitively inert’, i.e. it only wasted my time once, the time I spent reading it. I didn’t think about it afterwards, because it wasn’t attached to any enduring project or obsession or community that I was already tied into. So in some ways reading it had the same purpose as slumping in front of a filler TV show (just more appealing to me, because I like text). That inertness has its uses, though, because it left more space for different thoughts to my usual ones.

# Next month

I’ll try the ‘2 days on, 5 days off’ internet intermittent fasting diet. And I’ll keep going with Anki and see if gets less hassly.

You can’t tell from this newsletter, but I also did some physics. So I’ll keep on doing that too.

Cheers,

Lucy