Sliding Puzzle

In the third episode of my adventures in idea land I am confronted by idea mechanics and try to close the gap of a sliding puzzle. My adventuresomely struggles play out, this time, on the stage set by chapter 5 of Bernardo Kastrup's book The idea of the World. The main text of the chapter was also published in the journal Philosophies, but lacks the detailed footnotes present in the book.

The hard problem of idealism is objectivity. With objectivity I mean the set of observations, which could be easily explained if there would be an objective reality. Different versions of idealism have tried to solve this problem in different ways. But it is like a sliding puzzle: However you move the slides, the gap won't go away.

Bernardo is aware of the problem. Some of the observations making up the before mentioned set are even included in the basic facts which he takes as a starting point for his endeavor to infer his variant of idealism. His inferences lead to a detailed description on how mind works. I'll call that idea mechanics. Idea mechanics includes a variety of elements and processes: disruption, alters, perception, thought, thought complexes, extrinsic appearance, impingement, interference, transformation, association, disruption, etc. In the sliding puzzle analogy, idea mechanics corresponds to increasing the game to more slides.

I can still see the gap though. Try some thought experiments. For example, try to describe in terms of idea mechanics, how an alter goes about measuring the width of a sheet of letter paper with a ruler. Or, for example, try to describe in terms of idea mechanics, two alters who go about to measure the speed of light. In its present form idea mechanics is very flexible, drawing a lot from analogies. If you find satisfying solutions to thought experiments of the suggested kind, I'd hold that you use the flexibility of idea mechanics to melt the slides of the puzzle to your liking. If you instead insist to find a strictly formal way to express idea mechanics, I'd hold that would be akin to develop a complete theory of everything mental. From this theory of everything mental must then emerge, somehow, perceptions which are in accord with objective descriptions of reality like general theory of relativity or quantum mechanics.

I admit, Bernardo is very skilled in hiding the gap and making himself and his readers believe that it has gone away. The most direct quote I found, where he admits to the existence of the gap is this one:1

When the idealist says that experiences are like vibrations of consciousness, they do not necessarily concede primacy to spacetime over experience, but may mean simply that the spacetime-bound notion of vibration corresponds — in some admittedly metaphorical, illustrative, but nonetheless accurate sense – to an ineffable ontological fact.

I am not disturbed by the ineffable as such.2 I am disturbed by a position, which holds that idealism's problem of objectivity is solved by referring to the ineffability of expressing the solution.

I'm somewhat disgusted and exhausted. If I don't vanish after falling into a gap, there might be, perhaps, maybe, another episode. The London Underground, at least, got something right: Mind the gap.

p. s. I'm consciously on leave from idea land. But my subconscious seems to be adventuring forth. Three days later another question popped up: How does an alter learn to ride a bicycle? I leave the formulation in terms of idea mechanics to you. It's quite tricky.


  1. Bernardo Kastrup (2018) Conflating abstraction with empirical observation. Constructivist Foundations 13, 3. p. 341-347 -- URL https://constructivist.info/13/3/341.kastrup. See also episode one of the idea land adventure series. 

  2. Well, I am. But I accept it and try to live with it anyway.