The programmers who live in Flatland

You may need to explain more? I don’t think I missed the big idea - the metaphor of a separate plane or higher dimension that contains ideas not expressible in the ordinary one is a nice metaphor, and does apply well to some things (Kuhn’s paradigms in history of science come to mind, e.g. Newtonian Mechanics versus Relativity). I just don’t think it really applies well here. What business concepts or thoughts can you express in Clojure that you can’t express in Python or Rust?

> What business concepts or thoughts can you express in Clojure that you can’t express in Python or Rust?

If you only think about programming languages as a way to make money, the analogy of being stuck in Flatland is perfect.

some people only think about life as a way to make money. unfortunately coding was best-in-slot career for too long and these kinds of people hijacked the culture.

That's a bit of an ad feminam attack, isn't it? Just because I used the phrase "business concepts", somehow money is the only thing I care about when it comes to language choice? And yet, in my top-level post I said I went and learned lisp and clojure and read SCIP, and I will add that I did both of those things for fun. So no, I don't only think of programming languages as a way to make money. Elegance and expressiveness are interesting for their own sake. I trained as a mathematician; of course I think that.

But TFA was riffing on Paul Graham's old essay Beating the Averages, which argued precisely that the expressiveness of Lisp gave his startup a business edge. That was the context of my comment. I'd add that most of what most of us do in our day jobs is to use programming languages to make money, and there's no shame in that at all. And if you want to talk about why certain languages get widespread adoption and others not, you have to talk about the corporate context: there is no way around it.

But I'll rephrase my question, just for you: "what abstract problems can you solve or thoughts can you express in Clojure that you can’t express in Python or Rust?"

I’m sympathetic to looking down on the obsession with money. But there’s something deep and important about the monetary element. Engineering is about solving real-world, practical problems. The cost is a real factor in whether a potential solution is a useful one.

I think the money question is a red herring here. I’d phrase it more like: what problem in a user’s problem space is expressible only like this? And if the only user is the programmer, that’s alright, but feels more aligned with pure academia. That’s important, too! But has a much smaller audience than engineering at large.

Why are we limiting ourselves to business concepts?

The post isn't about Clojure or Lisp, it's about the author's journey as a programmer, and the mind-bending effect learning a Lisp had on their development. They're still in the midst of figuring it out, but a lot of people have been on this path before them. TFA has been written over the years by various authors about Prolog, or Haskell, or Smalltalk. In my case I would have written it about Lucid.

The interesting bit here isn't related to Clojure or Lisp, that's what people are chewing on because it's the surface level topic of the essay. The thing that interests me about this post is how it touches on the psychedelic nature of learning programming languages and what that does to one's perspective as a programmer.

So when you ask "what business thoughts can you express in the language", my response is it's not about what you can express, but more about "what new thoughts / ways of thinking has the experience of learning the language caused you to become aware of?".

Few people can go their whole lives writing Python and think all the possible thoughts there are to think about the shapes and forms programming can take. It's hard to develop a good sense for your own practice of programming if you never step outside and see it from other perspectives. It often takes exposure to completely new languages with different design points and abstractions to really give one perspective about their own practice.

The easiest one related to lisp is just the form of the syntax, which is surprising to many students. Most programmers don't even consider you can write (+ 1 1) and that's the same thing as (1 + 1). They don't think about the pros, or the cons, or why one might be better than the other, because every language they've used and ever will use writes it as (1 + 1). But as soon as they see Lisp, they immediately see something that changes their perspective about everything they have previous learned, and therefore will reshape how they approach programming in the future. It doesn't have to mean they will use Lisp going forward, but it does mean they will program in their language of choice with greater purpose. That's how we each hone our craft.

Add on homoiconicity, read/eval, programming as manipulating an AST, and meta programming, and you've got yourself a righteous trip.

Now, can people learn about those things from other sources, without encountering Lisp? Of course. Can you express those ideas in mainstream languages? Yes. But the point is many devs don't think those thoughts until they've had a psychedelic experience, it's very common, that we need to consider that it's part of one's growth journey as a programmer to have these experiences, so we should encourage it. The author of TFA doesn't have experience enough to make that point, as they are on the journey, which is why I brought Alan Kay's talk into context, since his perspective is from the other end of the journey.

Not GP, but … because the overwhelming majority of programming is done in support of businesses selling things?

I’m not just talking about people who program for a living. The majority of academic CS chooses its research directions because of what limits people are running into for business; even privacy-focused software has been commoditized by many business; a large amount of OSS development is by (and often paid for by the employers of) people working for money; heck, after Linus’s initial “just a hobby OS” period even Linux’s contribution base was primarily driven by business needs (even if those needs influenced it via “contributor had a problem at work and committed a solution for it upstream in spare time” as often as “paid contributor upstreamed a change on behalf of their employer”).

Yes and no. Most of the big new languages today are created to support the business of selling things because languages are expensive to make, they don't generate any profit themselves, so the only people who have enough money to fund their development are mega corporations, who act in self-interested ways.

But look at historical languages and why they were created:

Algol - to explore writing algorithms

Fortran - to help scientists write programs using typical math formulas

Matlab - to help write programs in linear algebra

Haskell - to explore lazy program evaluation

ML - to explore how to reason about proof automatically

C - to build an OS

Python - to interface with an OS

LISP - to formalize symbol processing

APL - to explore programs defined over arrays

LOGO - to help young kids to program computers

Prolog - to create a language around the idea of formal logic.

Smalltalk - to create an entire programming system, not just a language

(I've left out C++, Java, and JavaScript because I feel like those languages are mostly about serving business interests)

Pretty much the entire computing landscape over the past 50-70 years has been defined by people writing languages for reasons other than "this is for a business to use to make more money". So if we let business-driven interest dictate the future direction, we will have missed out on all the things that could have been. Would Haskell ever have been invented if businesses interests were the only concern for researchers?

How on Earth did you turn that into a sexist attack? Unless you two actually know each other IRL, and the GP shows sexism to you...

Fortran compilers were historically implemented by hardware vendors in order to sell their hardware, and this still largely holds true across the surviving implementations with the exceptions of GNU Fortran (obviously) and nagfor (commercial s/w product). There's a good reason that Cray Research's software group was initially part of its marketing department.

Oh, I didn’t say GP was making a sexist attack. If I thought that I would have said it clearly and distinctly. Ad feminam is just the feminine version of ad hominem. I like Latin.

The compilers were, but Fortran wasn't invented so that hardware manufacturers could sell their wares to scientists.

It was invented so that IBM could sell more gear to the institutions that employed them.