I want to know arguments for Space realism (space is real, mind independent substance or system of relations), because Kastrup seems to claim space and time are modes of perception ala Kant and Schopenhauer.

What are the responses of professional philosophers to his work?

  • I've seen his videos. He says everything is consciousness. I don't understand what that even means. Even for my consciousness to operate, there is continuously non-conscious processes going on. When I use language there's a combination of conscious and non-conscious processes. When I recall something, the memory just appears... but the process by which the memory appeared to my consciousness is not happening within consciousness. If everything is consciousness, is it consciousness that keeps the laws of physics going? Nov 16, 2021 at 14:37
  • Here's video about Locke and Berkeley. youtube.com/watch?v=WJzQF7eknKA&t=5s Watch at 36:37. Magee presents objections that are natural when presented with idealism. (laws of physics... object persistence etc.). Now Berkeley has an answer. There is a super-consciousness (god), conscious of everything at all times even at the micro-level keeping everything going even when finite consciousnesses aren't watching. I don't think this is Kastrup's view. So how would Kastrup respond to these objections? Nov 16, 2021 at 14:56
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    @AmeetSharma B. Kastrup is essentially analytic Advaita Vedanta, and his dissociation theory is a derivative from the Eastern doctrine of dualism. So yes, in the eyes of Kastrup there is ultimate consciousness (like Brahman). Nov 16, 2021 at 15:12
  • This question reads like word salad. Are you saying that because Kastrup says that space and time are ideal, we should say they are real, pending any argument to the contrary? The question of the Kanti's anti realism about space and time can be read about here plato.stanford.edu/entries/kant-spacetime
    – user56770
    Nov 17, 2021 at 0:13

1 Answer 1



It's just metaphysical speculation. Those aren't exactly prone to truth or falsity evaluations.

Long(er) answer:

The denial of spacetime is a speculation that is in line with theories of certain physicists ("Spacetime is doomed"). Kastrup heavily relies on this particular approach in physics that considers a "top-down" view of physics privileged, as opposed to the "bottom-down" one. In other words, it is the primacy of the observer and observation, and thus, the primacy of consciousness. For example, Hawking and Hertog say:

if one does adopt a bottom-up approach to cosmology [God's eye view], one is immediately led to an essentially classical framework, in which one loses all ability to explain cosmology’s central question—why our universe is the way it is.


The framework we propose is thus more like a top-down approach to cosmology, where the histories of the universe depend on the precise question asked.

And John Wheeler complements this:

Each elementary quantum phenomenon is an elementary act of ‘fact creation.’ That is incontestable. But is that the only mechanism needed to create all that is? Is what took place at the big bang the consequence of billions upon billions of these elementary processes, these elementary ‘acts of observer-participancy,’ these quantum phenomena? Have we had the mechanism of creation before our eyes all this time without recognizing the truth?

That spacetime is not objective but imposed by subjectivity is in accordance with Schopenhauer's views. In the words of Donald Hoffman (who holds similar views):

Spacetime is a data structure that we create to represent fitness payoffs and how to get them.

Therefore, each observer evolves to have a different interface into [whatever is at the bottom of all of this]. Spacetime and the physical world is an illusion akin to Maya.

Kastrup goes very close to Carlo Rovelli who claims that the world we see is relativistic and up to the perceiver. However, he departs from Rovelli in that he postulates a universal kind of consciousness which is the source of objectivity.

From Here I part ways with Rovelli:

Rovelli and I are in full agreement when it comes to our view of the nature of physical reality: there is no absolute world of tables and chairs with defined mass, position, momentum, etc., out there, but instead an entirely relational world.


In my view, if the physical world has no standalone reality and is entirely relational, then there necessarily is a deeper, by definition non-physical but absolute (in the sense of not being relative) layer of reality that grounds the physical world, and of which the physical world is but a measurement image akin to a set of dials. I've known for a while now that Rovelli isn't comfortable with this conclusion of mine

Kastrup thinks that at the bottom there is a universal consciousness that works through quantum excitations (or the "will", in the words of Schopenhauer). Here, There are some obvious parallels to the idea of Brahman in Advaita Vedanta philosophy. Especially that Kastrup's argument relies on the fact that conscious agents dissociate from the whole like in multiple-personality disorder, which is akin to the Eastern doctrine of dualism. The "cure" is to be eventually reunited with the whole.

Of course, the drawbacks and the criticism are clear. This is not actually a scientific theory (not even a hypothesis), but well-argued metaphysical speculation. If you play this game, then you play at your own risk. Ultimately, arguments both ways are "nullified" because they are not really testable, nor falsifiable.

But if you insist, then see the arguments of the opposite camp. Kastrup's arch-enemy is Daniel Dennett who holds the opposite claim; all is matter, and consciousness is a kind of illusion. If you want to find good arguments for it, read "Consciousness Explained*".

*- ... away

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    Interesting, but isn't Kastrup's denial of spacetime radically different from that of theoretical physicists? Some physicists (as I understood it) claim spacetime emerges from other things, such as quantum entanglement. However Kastrup claims spacetime is literally in our heads. Before humans (and other animals) there just was no such thing as space, and that seems incomprehensible to me.
    – ArAj
    Nov 16, 2021 at 20:35
  • Yeah.Claim that spacetime cannot function as a primitive (or objective reality) is widely accepted for physicists which don't accept local realism. If you want the whole argument with examples, read the 6th chapter of Donald Hoffman's "Case Against Reality", as I don't remember well. And, spacetime is not so much "in our heads", but in consciousness, as for Kastrup, consciousness precedes "heads", and thus, it does not require heads; it is the ontological primitive of the universe. So, everything arises from consciousness. Spacetime is like the desktop and the objects are like the icons. Nov 16, 2021 at 21:06
  • Also, apart from Hoffman's book, you can read Kastrup's "Decoding Schopenhauer's Metaphysics: The Key to Understanding How It Solves the Hard Problem of Consciousness and the Paradoxes of Quantum Mechanics" as it also tells how it deals with spacetime. It's a short book but possibly elucidates Kastrup's system the most. Nov 16, 2021 at 21:10
  • @ArAj "but isn't Kastrup's denial of spacetime radically different from that of theoretical physicists" Well, of course it is, he's doing his own metaphysics where everything is Mind :) Other physicists like L. Susskind argue for holographic principle, a 2D plate that outputs three-dimensional object (illusion). Or John Wheeler, who thought that the information is fundamental ("it from bit"). Kastrup brings certain arguments but makes his own metaphysical claims. Nov 16, 2021 at 23:31
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    @ArAj, I think Kastrup would say everything... space/earth/moon etc... are all happening "within" consciousness. Nov 17, 2021 at 7:44

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