That's a great point.

I read the book and indeed, there's something of that dichotomy between what he calls "system 1" and "system 2".

System-2 is the very thorough, conscious thought; the visual or otherwise perceptible, representable as abstract but tangible objects (like please think of an elephant: this thing you see right now in your mind is an abstract but tangible object). System-1 by comparison is more intuitive, and I think can typically be illustrated by procedural memory: things you know but forgot how you learned, like riding a bike or playing chess.

In interviews he explains that, while most questions would confuse system-2 for "intelligence" or "logic", it's really not: a chess master for instance uses system 1 a lot to instinctively select only strong moves, or a chef uses system-1 to select only compatible and worthy ingredients — and then system-2 may think in depth about this small subset. The idea is that the system-1 of a master would beat the hell out of any layman's system-2 for a given skillset.

So when you really internalize, learn something, it's like the schema for it in your brain moves gradually from the system-2 space to the system-1 space so to speak. In many ways, there's no possible mastery without system-1. That's what makes "expertise" as we call it, this "6th" sense for a domain.

Video games are so much like that: first you have to think about everything, but gradually it becomes 'second nature' like walking or driving.

Now here's my point: the whole process of "thinking to oneself" is system-2. All of it. By definition, if we use Kahneman's term. System-1 is more like the underlying parameters of a thinking space (like knowing the rules at a deep level of instinct), wherein system-2 manipulates variables.

Let's risk the analogy that:

- system-1 feels like each person's particular 'optimization' of 'brain hardware' or 'OS': for instance, I may have a GPU-like skill or such a "driver" or "ad hoc firmware" to process math (because training); you may have a great NN-like skill to process consulting problems in your domain (result of years of experience); it's all related to training and personal story i.e. compounded construction, effort over time.

- Whereas system-2 is the software layer, the apps, this inner-userland where you push buttons and 'see' results, and largely transmissible through communication, teaching (again in my words, system-2 objects are 'representable', abstract but tangible, as evidenced by the fact we can take objects from brain to brain). You can do almost anything in system-2, but most of it is weak and orders of magnitude slower absent of further optimization.

I think it warrants more in-depths discussions and research probably, but that's my ballpark view. What's intriguing about this "inner speech" discrepancy in thinking is precisely that systems-2 are commonly thought to be relatively standard computers between human beings (again, I can take an app from mine and teach it to yours, so there's some level of direct compatibility there). Evidently, that's not entirely true, and the deeper question is whether it points to a different architecture or simply a matter of perception; how isomorphic are different approaches at the end of the day.