To be sure, the quoted text in the parent comment is itself the linked essay’s quotation of Paul Graham.

Whether logically rigorous or not, that excerpt seems to be the essay’s author’s way of rhetorically opening his reflections on the idea that writing verbally crystallizes thought.

As a reader, I do not believe that the author is making a claim that the quoted Paul Graham statement, reduced to symbolic logic, is in all respects valid or sound.

How is it flawed logcally? Seems perfectly correct to me. Although I'd agree it's a bit over-literal. As if the emotional workings of the human mind can be precisely reasoned about (i.e. precisely enough to say "always").

Regardless, I've experienced this effect a lot when writing design docs. Iteration and objective criticism on a tangible thing (a doc) is an extremely effective way to see the problem from all sides.

Taking the statement completely out of context, it states : if A implies B, then not A implies not B. This is a logical flaw.

The correct statement from a logical point of view is: if A implies B, then not B implies not A.

In this case, even if writing down your ideas makes them more precise, there might be other methods that make your ideas more precise. Again this is just the logical point of view, out of context.

> Taking the statement completely out of context, it states : if A implies B, then not A implies not B. This is a logical flaw.

The statement in TFA is not that though. Instead, it is "if A implies B, then not A implies not C."

  A: writing about thoughts
  B: thoughts become more complete
  C: thoughts are most complete

If "A implies B" is true, then it also doesn't matter if other methods also make your ideas more complete, because "A implies B" means that writing would make them even more complete, therefore "not C."

You're perfectly right. It is indeed perfectly logical then. It could be reformulated like this: if f(A) > f(not A) then f(not A) is not maximal.

f: a function indicating how complete the thoughts are.

A: writing about thoughts.

What books can I read to reason like this?

EDIT: shortened sentence

This might sound strange but a book on real analysis or topology that walks through proofs could be one.

+1, pg is using a pretty typical argument you see in analysis/topology.

If you want to get to real analysis/topology the typical sequence is

1. Logic and Set theory (recommendation: How to Prove It, Velleman)

2. Linear Algebra (don't have a good recommendation)

3a. Real analysis (recommendation: PMA, Rudin)

3b. Topology (recommendation: Topology, Munkres)

I'm not sure I'd recommend learning math. It's an extremely expensive skill -- though pretty valuable in the software industry. People who go learn math are generally just drawn to it; you can't stop them even if you wanted to.

But be aware, (1) you'll have no one to talk about math with. And (2) you'll be joining a club of all the outcasts in society, including the Unabomber.

Disclaimer: I'm not OP and I haven't read the full post yet.

But the quote above says "If..." and then makes a statement that isn't true and then having a conclusion based on that false premise. I can tell you it isn't true because I can recall countless times in the last few months alone where writing down my ideas has resulted in a muddier thought; lost ideas while writing them down; confusing me and missing some parts; it does not "always make them more precise and more complete". So the rest of the statement is just silly.

Sure, sometimes writing down ideas helps clear things up. Most times even. But always?! Definitely not.

The deduction is flawed because the success of one method (thinking with writing) does not necessarily disprove the success of other methods (such as thinking without writing).

You're objecting to the premise, not the conclusion*. The deduction is valid for the premise (the part in the 'if'). Well, assuming you accept that an idea that can be "more complete" isn't "fully formed", but I'd say that's definitional.

* Although it's not really right to use this kind of language here (premise, conclusion, deduction). It's a casual statement, so I suppose people can somewhat reasonably argue about it, but the assertion is tautological ('if something is incomplete, it isn't fully formed').

The keyword is "always". IF writing about something always improves it, that implies it cannot ever reach full potential without writing about it.

Or with writing about it. But there's an implicit "if you haven't already written about it". We might wonder what other implicit preconditions there are.

Similarly, if walking North always brings you closer to the North Pole, then you can never reach the North Pole without walking North, or at all. But look out for oceans.

There's no logical flaw here. An idea can't be fully formed, if it could be more precise and more complete.

Sure, and even ideas that have been written about can be more precise and complete, perhaps by writing more about them, for example, so no one has fully formed ideas by this logic.

And that’s probably true. I doubt anyone has ever expressed an idea that couldn’t be amended, clarified, or expanded upon in some way.

Depends on the idea. To me the whole article was too generic or handwavy without giving specific examples of what kind of ideas are actually fully formed and which are not.

What is a definition of an idea that is fully formed and that is sufficiently complex enough?

But also, if more writing can always make the idea “more complete,” then no one at all (even the people who write) has any “completely complete” ideas.

> "If writing down your ideas always makes them more precise and more complete, then no one who hasn't written about a topic has fully formed ideas about it."

> Apparently, even writing it down didn't help the author with this flawed deduction.

I think that it can be rescued, at some expense of awkwardness, by grouping not as one would expect ("(fully formed) ideas"), but in a slightly non-standard way:

> "If writing down your ideas always makes them more precise and more complete, then no one who hasn't written about a topic has fully (formed ideas about it)."

That is, if you haven't written about the topic, then you haven't understood it as precisely and completely as you could. While this is obviously exaggeration, I think that it's (1) logically consistent, (2) possibly what pg meant, and (3) a useful slogan, even if intentionally over-stated.

<div class="commtext c00">Yes this is some terrible logic, but the idea is true.

Writing about something fixes (most) wrong thoughts, and since you are wrong in 99% of cases you can safely say that you are wrong unless you have written about it.</div>

"If allspice makes food taste better, than no one who doesn't use allspice can cook well."

The analogy is probably something more like:

Salt is necessary to bring out the flavor in pretty much all food. So no one who doesn't use salt has made a good meal.

Because salt is much more irreplaceable than allspice in cooking, just like writing is difficult to replace in honing ideas.

> Apparently, even writing it down didn't help the author with this flawed deduction.

... or this writing improved an even more flawed original.

Or it gave author unwarranted confidence in a flawed argument on the basis of a flawed assumption.