Bernardo Kastrup: A Solution to the Mind-Body Problem


An Ontological Solution to the Mind-Body Problem


The mind-body problem, which addresses how conscious experience relates to physical matter, is deeply entwined with ontology. Bernardo Kastrup’s paper, “An Ontological Solution to the Mind-Body Problem,” presents an idealist ontology that he argues is more consistent with empirical observations and more parsimonious than physicalism and bottom-up panpsychism. This article explores his proposal that spatially unbound consciousness is nature’s sole ontological primitive, with all living organisms being dissociated alters of this consciousness.

Understanding the Mind-Body Problem

The mind-body problem is traditionally framed by two main ontologies:

  1. Physicalism posits that reality is made up of irreducible entities outside and independent of experience. Consciousness, under this view, emerges only from complex arrangements of these entities.
  2. Bottom-up Panpsychism suggests that at least some of these primitives have experiences, and complex experiences arise from combinations of these experiencing primitives.

Kastrup contrasts these views with idealism, which holds that all physical entities exist only within consciousness.

Basic Facts of Reality

Kastrup starts by stating four basic facts that are verifiable through observation:

  1. There are tight correlations between reported private experiences and observed brain activity.
  2. We all seem to inhabit the same universe.
  3. Reality follows patterns and regularities independent of personal volition.
  4. Macroscopic physical entities can be broken down into microscopic parts.

These facts are more easily reconcilable with physicalism and panpsychism than idealism, at least prima facie.

Idealism and the Nature of Consciousness

Kastrup proposes that consciousness is an ontological primitive—uncaused and irreducible. He suggests that the brain’s activity is accompanied by inner experience, implying that the universe may be akin to a vast “nervous system,” where all physical activity is accompanied by experience. This leads to the idea that the entire universe is associated with a unitary consciousness.

Dissociation and Private Experiences

To reconcile the notion of a unitary consciousness with our private, individual experiences, Kastrup introduces the concept of dissociation. This psychiatric condition involves a disruption in the normal integration of consciousness, leading to fragmentation. He likens our individual experiences to dissociated alters of a single, universal consciousness.

Comparison with Other Ontologies

Kastrup’s idealist ontology seeks to address the limitations of physicalism and bottom-up panpsychism by offering a model that avoids the hard problem of consciousness and the subject combination problem.

  1. Physicalism struggles to explain how specific physical arrangements generate experience.
  2. Bottom-up Panpsychism fails to adequately combine individual experiences into a unified consciousness.

Concluding Remarks

Kastrup’s ontological framework positions consciousness as the foundation of reality, proposing that all living organisms are dissociated parts of a single, unbound consciousness. This perspective offers a parsimonious and explanatorily powerful solution to the mind-body problem, potentially surpassing both physicalism and bottom-up panpsychism in coherence and simplicity.


In summary, Kastrup’s work provides a compelling argument for idealism as a solution to the mind-body problem. By positing that spatially unbound consciousness is the sole ontological primitive, he offers a framework that integrates the empirical facts of reality while addressing the major challenges faced by physicalism and panpsychism. His use of the concept of dissociation to explain individual experiences within a unitary consciousness presents a novel and intriguing approach to understanding the nature of reality.