What would a possible solution to the hard problem of consciousness look like?

Question

The hard problem of consciousness is stated as- 'why objective, mechanical processing can give rise to subjective experiences.'

The reason I ask this question is that if we do not even know what a possible solution to this problem should look like, then perhaps this is an unsolvable problem.

So, my question is, what would a possible solution look like? What issues should it address so as to qualify as a solution?

For example, if I have a problem to produce a theory that explains the behavior of a physical system, then a possible theory should constitute a way to mathematically represent the state of the physical system and a law as to how this state evolves over time, etc. This can be formalized using differential equations, etc.

What would an analogue theory to solve the Hard problem of consciousness look like?

Answer 1

A solution to the hard problem of consciousness would be a mathematical formula to determine what consciousness is present, if any, in a formally described physical system, and what that consciousness is experiencing.

We can think of the solution as a "black box."

• The black box takes as input a mathematical description of a physical system. Precisely what form this description takes is open to discussion. For example, it might be a set of differential equations giving the time evolution of the physical system, depending on its inputs.
• The black box yields as output a mathematical description of any consciousness present in the physical system. The precise form of this description is also open to discussion, but perhaps it would involve variables for the different elements of qualia, similar to the pixels on a computer screen, and describe their evolution over time, perhaps using differential equations.
• The output yielded by the black box should substantially agree with an individual's direct observations of their own consciousness.
• The black box should be a fairly simple mathematical theory, in accordance with Occam's razor.

Anticipating some objections:

1. There are philosophers who argue that this is not a solution at all, that there is an insurmountable gap between the mathematical description of qualia akin to pixels on a computer screen, and the actual experienced qualia. Perhaps there is such a gap. It doesn't seem that gap can be crossed with anything we could ever write down; there will always be a difference between the words written and the actual qualia. However, the black box would at least be a substantial stride forward in our understanding, and would model the mathematical structure of the qualia.
2. There are philosophers who think that this is inherently impossible for some reason. Non-functionalists, for example.

Answer 2

I am old now, but I remember in my teens being introduced to the idea of dimensional analysis in physics, and it struck me then, as it still does now, that it would be surprising to find a physical explanation for consciousness, since that would require reducing consciousness into some kind of unit based on length, mass, time etc, which seems inherently unpromising.

Perhaps information theory might offer a more useful perspective. Imagine a computer screen upon which is printed what seems to be a random stream of numbers. Physics can only go so far in explaining the phenomenon of the numbers on the screen. Physics can account for why certain pixels are more luminous than others, by reference to electrical potentials in circuits and so on, but it cannot account for the numbers being meaningful symbols, and it cannot impart meaning to them. Are they just a random stream? Are they the face of Beyonce encoded in some way? Are they my bank details encrypted with some hash? Those questions can't be addressed by physics, although you do need physics to count for the way in which the numbers are displayed by the underlying substrate of the computer screen. I suspect some kind of analogous explanation will be required for consciousness. There will be an enabling workspace, as it were, for consciousness, which is accounted for by the electrical states of neurons in the brain (in the same way that pixel intensities can be accounted for by electrical states in the computer display), but consciousness per se may be a level of abstraction above that, incapable of being described by physics alone.

Answer 3

Assume the Universe to be well modeled by a Turing Machine (TM), with the data on the tape encoding the current state of the Universe. Then, to solve the hard problem of consciousness, we need a theory that can do the following things-

1. Give a method to (approximately) recognize which bit string on the tape of this TM are 'conscious'.
2. Propose an extra law that formally associates these 'conscious' bit strings with an entity called 'conscious observer'.
3. Study the different types of subjective experience and their relationship with each other.
4. Study if the conscious observer is just a mute observer or can also have influence on the TM

Some comments-

• Given the state of the universe, it may not be easy to recognize which subsystem is conscious and which is not. For example, I am tempted to say that every time there is a functional brain, then it is conscious, but even AI may become conscious in future, so it is tricky.
• The law that formally associates these 'conscious' bits with entities called 'conscious observers' basically explicitly acknowledges that we live in a Universe which, when modelled by a TM, has extra entities called 'conscious observers' associated with it.
• The theory should define different types of conscious experiences, like sensation of 'redness', 'heat' or 'fear', and study the relationship between these entities.
• If the conscious observer has influence on the TM, is the influence algorithmic? If yes, then it would be equivalent to it having no influence, because any such algorithm can just be incorporated in the original TM. On the other hand, if the influence itself is not algorithmic, then this raises the question- Is the universe well modelled by a TM?