Breaking Down the Problem of Consciousness

Below you will find three different breakdowns for what a scientific theory of consciousness must be able to account for, formulated in slightly different ways.

First, David Pearce posits these four fundamental questions (the simplicity of this breakdown comes with the advantage that it might be the easiest to remember):

  1. The existence of consciousness
  2. The causal and computational properties of experience (including why we can even talk about consciousness to begin with, why consciousness evolved in animals, etc.)
  3. The nature and interrelationship between all the qualia varieties and values (why does scent exist? and in exactly what way is it related to color qualia?)
  4. The binding problem (why are we not “mind dust” if we are made of atoms)

David Pearce’s Four Questions Any Scientific Theory of Consciousness Must Be Able to Answer

Second, we have Giulio Tononi‘s IIT:

  1. The existence of consciousness
  2. The composition of consciousness (colors, shapes, etc.)
  3. Its information content (the fact each experience is “distinct”)
  4. The unity of consciousness (why does seeing the color blue does not only change a part of your visual field, but in some sense it changes the experience as a whole?)
  5. The borders of experience (also called ‘exclusion principle’; that each experience excludes everything not in it; presence of x implies negation of ~x)

Giulio Tononi’s 5 Axioms of Consciousness

Finally, Michael Johnson breaks it down in terms of what he sees as a set of what ultimately are tractable problems. As a whole the problem of consciousness may be conceptually daunting and scientifically puzzling, but this framework seeks to paint a picture of what a solution should look like. These are:

  1. Reality mapping problem (what is the formal ontology that can map reality to consciousness?)
  2. Substrate problem (in such an ontology, which objects and processes contribute to consciousness?)
  3. Boundary problem (akin to the binding problem, but reformulated to be agnostic about an atomistic ontology of systems)
  4. Scale problem (how to connect the scale of our physical ontology with the spatio-temporal scale at which experiences happen?)
  5. Topology of information problem (how do we translate the physical information inside the boundary into the adequate mathematical object used in our formalism?)
  6. State-space problem (what mathematical features does each qualia variety, value, and binding architecture correspond to?)
  7. Translation problem (starting with the mathematical object corresponding to a specific experience within the correct formalism, how do you derive the phenomenal character of the experience?)
  8. Vocabulary problem (how can we improve language to talk directly about natural kinds?)

Michael Johnson’s 8 Problems of Consciousness

Each of these different breakdowns have advantages and disadvantages. But I think that they are all very helpful and capable of improving the way we understand consciousness. While pondering about the “hard problem of consciousness” can lead to fascinating and strange psychological effects (much akin to asking the question “why is there something rather than nothing?”), addressing the problem space at a finer level of granularity almost always delivers better results. In other words, posing the “hard problem” is less useful than decomposing the question into actually addressable problems. The overall point being that by doing so one is in some sense actually trying to understand rather than merely restating one’s own confusion.

Do you know of any other such breakdown of the problem space?



  1. Pingback: A Big State-Space of Consciousness | Qualia Computing
  2. sbpptm · November 22

    Very nice. Thank you for writing this.


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