Max Tegmark publishes a preprint of a paper arguing from physical principles that consciousness is “what information processing feels like from the inside,” a position I've previously articulated on lesswrong. It's a very physics-rich paper, but here's the most accessable description I was able to find within it:
If we understood consciousness as a physical phenomenon, we could in principle answer all of these questions [about consciousness] by studying the equations of physics: we could identify all conscious entities in any physical system, and calculate what they would perceive. However, this approach is typically not pursued by physicists, with the argument that we do not understand consciousness well enough.
In this paper, I argue that recent progress in neuroscience has fundamentally changed this situation, and that we physicists can no longer blame neuroscientists for our own lack of progress. I have long contended that consciousness is the way information feels when being processed in certain complex ways, i.e., that it corresponds to certain complex patterns in spacetime that obey the same laws of physics as other complex systems, with no "secret sauce" required.
The whole paper is very rich, and worth a read.
Hm. Trying to come up with a matching definition of "suffer" in this context.
How about "perceiving damage". But that is not conscious. That could be said about any minimal (neurological) circuit.
"Perceiving damage to self". But that recurses to "self". And it we avoid "self" by using "actor" (which is more specific but needs a simpler concept) we are back where I was.
Also "suffer" implies some kind of stress. Some mode that deals with existential danger. Which can be a) act actively to avoid that danger or b) display signals to some perpetrator to reduce the danger or c) failure due to (partial) break down of essential systems.
But if I use just "being in a state of suffering" (as above a) to c)) this is still not conscious so I guess something must be missing.
Suffering is not about damage. I'm not even sure it's about aversion. Suffering seems to be tings like boredom, sadness, and frustration. The best hypothesis I'm found so far is "internal conflict". The primary capability that enables suffering seems to be desire.
Pain and damage doesn't cause suffering; it's wanting to get away from it and being unable to that does. If you feel a jolt of excruciating pain, it disappears entirely when you flinch away, and you negate it's source to remove the risk in the future, you'll probably experience it in a highly positive way.