What is Alan Kay’s view on analytic idealism by Bernardo Kastrup?
Last Updated: 25.06.2025 06:11
" ... as far as the propositions of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality."
In Philosophical terms, the 5 premises above are essentially epistemological. Wikipedia again:
The writing style of this book is nicely clear, but very repetitious. There is an air of “I need to explain this many times because you are probably not understanding”. The last part might very well be the case, but repetition doesn’t help.
Here are my reactions as of Nov 6th.
Analytic Idealism in a Nutshell: A Straightforward Summary of the 21st Century's Only Plausible Metaphysics
Epistemology, the philosophical study of the nature, origin, and limits of human knowledge
Why is my elder sister so mean?
We create a kind of a map that is its own internal world, and — if we are sophisticated — we realize that our map should not be called “reality”, and at best we have to negotiate between the limitations of our mappings and the phenomenal evidence we can detect. This internal world each human has is sometimes called our “Private Universe”.
Kastrup starts out with his version of this idea — one I’ve also used many times in talks — that
I wonder if I understand enough about the general subject area — Philosophy in general, and Metaphysics in particular — to make it worthwhile to share my opinions? My thought patterns are primarily within the general outlooks of science, math, engineering, and some of the arts: musical, visual, theatric, literate, etc.
Geometry and Experience, Lecture before the Prussian Academy of Sciences, January 27, 1921
This world unfolds on its own, according to its own inherent dispositions, and reveals some phenomena our senses (and sense aids) can pick up
Human reason can recognize and model what it thinks are regularities in this phenomena, and in some cases can predict future phenomena
I’ve ordered it — it is not out yet — due to arrive Nov 1st this year (2024).
I got his book — Analytic Idealism in a Nutshell: A Straightforward Summary of the 21st Century's Only Plausible Metaphysics — and have read it.
what we think of as “out there” is actually going on in our brains: “in here”, between our ears.
Metaphysics is the study of the most general features of reality, including existence, objects and their properties, possibility and necessity, space and time, change, causation, and the relation between matter and mind. It is one of the oldest branches of philosophy.
See you in November …
The ideas in it are put forth as an essay into Philosophy, particularly focused on Metaphysics (the nature of Being itself).
Manufacturing PMI® at 48.5%; May 2025 Manufacturing ISM® Report On Business® - PR Newswire
Analytic Idealism In A Nutshell is also a book that provokes mulling. The subject matter is a few levels more murky and abstract than TOOCITBOTBM, but trying to understand what is being attempted and pondering whether its arguments actually hold water can be quite enjoyable, and to some extent, illuminating.
Kastrup adds several other postulates in his Introduction. Here are his additional four (partially quoting):
For example, an argument of the form “because the thing in question is not this, this or this, it must be *that*” only works in reasoning/logic/math, etc., if you can first show that you have enumerated all the candidates and eliminated all but one.
I think most scientists — including me — would agree that these five are highly likely. Kastrup calls these realism.
Kastrup likens the internal map to a dashboard inside a hermetically sealed airplane where the instruments provide enough information to fly the plane, but do not at all resemble what we’d see if we could look outside the plane (this is a quite good example/analogy).
Wikipedia’s definition is good enough:
Trump travel ban rattles immigrant communities across U.S. - The Washington Post
There is an external world out there, beyond our physical minds
I like — and subscribe to — Einstein’s reminder to scientists in his 1921 talk in Berlin:
However, I should reveal a personal prejudice against what I understand is the basic idea. As with most prejudices, it doesn’t have much substantive behind it, but I’ll be trying to keep this in mind when I read the book.
Google’s Pixel 10 phones will reportedly launch on August 13th - The Verge
The needed enumeration is not done here, and I don’t think it can be done.
Complex phenomena can be “sufficiently accounted for in terms of simpler ones” (basically non-linear reductionism).
I will try to fit the rest of this within a Quora-sized (albeit one still too long) answer.
And, he starts arguing right away. It is not at all clear to me that his arguments (a) work, and/or (b) perhaps can be made at all. I am prejudiced in favor of essays which spend a lot of their front matter in exposition and follow this groundwork by argument. This is not done here.
Taken together, it looks as though these premises of Analytic Idealism make it difficult to do more than claim any ultimate knowledge about anything “out there”. I.e. I think that Kastrup can claim his thesis as a proposition — but, given the premises, I don’t think he can substantiate his claim. As Einstein pointed out, logic/math/language/inference with the aim of “certainly” with regard to chains of thought will not refer to “reality” but only — if done as well as possible — to the consistency of the arguments.
I’m sure that I need to read his forthcoming book in order to attempt an answer:
Overthinking is killing me day-by-day. What should I do?
A book that I’ve enjoyed very much — and which provoked much mulling — was Julian Jaynes’ “The Origin Of Consciousness In The Breakdown Of The Bicameral Mind” (TOOCITBOTBM). It is perhaps my favorite of this kind of book. I doubt its conclusions, but thinking about the issues, evidence, and forms of argument have. quite widened my thoughts over the years.
One way to approach this is to ask whether his initial premises — which I agree with — actually allow his thesis — that Being is a kind of universal mentality that is very unlike the internal mappings that physical scientists try to make of Nature — to be successfully argued.