Panpsychism means something like 'all has a mind' or 'everything has a mind', from the Greek for everything (pan) and the Greek for soul/mind (psyche) and it has a long history in metaphysical philosophy, for those trying to explain that the mental aspects of the world are a fundamental feature of reality. I suspect, on the surface, it seems like panpsychism might have answers for people who've had an experience of oceanic boundlessness, as researchers call it: feelings of one-ness with the world, or a sense of eternity that often comes with the insight that there is some kind of universal consciousness to the world. Alas, I doubt you're going to find it very satisfying. Let me tell you why.
What does panpsychism care about?
Panpsychism, as a way of trying to link the human sense of consciousness with some kind of universal consciousness or eternal 'fabric' of reality reaches right back to antiquity. But at the core it's always really been about what we call now the 'hard problem of consciousness'.
Very broadly, the idea is that the fundamental nature of existence is material---there is only material stuff in the world we inhabit. We study matter, and the interactions of matter, and these things explain the goings on of worldly things. Perhaps there are other kinds of things than material things, but no one can seem to find any evidence for them. Except in the case of consciousness. Indeed, the only undeniable experience is the fact that we experience anything at all. We experience the redness of the colour red; the feeling of hunger; the pain of being slapped; the beauty of some natural vista.
But there is absolutely no reason for us to experience any of these things, in a material world. Science has nothing to say about the qualitative properties of things, only the physical ones. Colours are features of things that reflect light. Pain is cell damage. Hunger pangs are stomach contractions. The qualities of colour, of pain, of hunger, are left unexplained. They seem to exist only in our minds as properties of our subjective experiences. Chalmers, who coined the term 'hard problem', puts it nicely (pdf):
... even when we have explained the performance of all the cognitive and behavioral functions in the vicinity of experience—perceptual discrimination, categorization, internal access, verbal report—there may still remain a further unanswered question: Why is the performance of these functions accompanied by experience?
There is no question that experience is closely associated with physical processes in systems such as brains. It seems that physical processes give rise to experience, at least in the sense that producing a physical system (such as a brain) with the right physical properties inevitably yields corresponding states of experience. But how and why do physical processes give rise to experience? Why do not these processes take place "in the dark," without any accompanying states of experience? This is the central mystery of consciousness
You could, as Chalmers went on to do, imagine a zombie or automaton---a person who went about the world behaving in all the ways in which a person would be expected to, but with absolutely no experience to speak of. Simply mechanically acting and reacting to the world around it.
Importantly, consciousness is different from conscious access. We're not talking about how we can reflect on our feelings. It's difficult to explain the reflective self. But panpsychism doesn't care about that. It cares about the fact that there is this apparently non-material mental stuff---the capacity for experience---that doesn't map on to material stuff in any sensible way.
Solutions to the hard problem that aren't panpsychism
There are three seemingly obvious solutions to this problem.
The first is the non-materialist view. We might say that there is both material stuff and there is a seperate kind of experience stuff. This is where dualism sits, for example---the idea that there is a distinction between the mind and the body, or the body and soul. This is, of course, sliding out of fashion in an increasingly secular world, but it can be a secular position. The issue is that it leaves an important gap: how, exactly, does something immaterial interact with with something material? There is obviously some cross-over here---we experience this non-material experience stuff with our very material bodies. What, precisely, allows that to happen?
There are two sort-of materialist categories that try to step into that gap. The first are the emergentists. We could say that consciousness is just some kind of special property of the material world that emerges from specific configurations of material stuff. When we put together two oxygen molecules and a hydrogen molecule, liquidity emerges. When we arrange neurons in a certain way, consciousness emerges. Unfortunately, this doesn't actually solve our problem, really. We have a complete understanding of what's going on with molecules that allows them to produce liquidity in certain configurations. We have absolutely no idea how consciousness emerges from a configuration of brain cells. We've just detailed the exact same gap that the non-materialists fail to bridge: how does the material stuff interact with the experience stuff? Just because it feels more palatable doesn't mean we're any closer to solving the problem.
The second group of materialists we can call 'illusionists'. We might say consciousness is simply an illusion. Movies produce the illusion of motion by flashing still images so fast we process them as a moving image. Brains produce the illusion of consciousness by representing complex patterns of neural activity as simple experiential properties. Maybe experiences are simply some kind of 'edited digest'2 of all the events going on in the brain. Just a general sense of the shape of things. Unfortunately, this also doesn't really seem to do anything at all to bridge our gap. The experience of consciousness is consciousness, illusory or not. Illusory pain makes pain no less painful. We still have to explain how the illusion translates into an experience of the illusion.
Panpsychism doesn't even care about the gap
You might have been thinking that panpsychism was going to have a neat solution to this little gap the others fail to bridge. You'd have been wrong. Panpsychism, at least in it's modern form, doesn't even really seem to care about this gap. It's trying to do something a little bit different.
The issue that panpsychists have with the materialist view is that there is a circularity in their approach. They only ever explain things in terms of their behaviour around other things. They never approach explaining the intrinsic nature of those things.
Physics, for example, only ever explains what things do. It doesn't ever try to explain what things are. Physics can tell us that atoms have a certain mass, for example. But mass is characterised by behavioural properties: gravitational attraction or resistance to acceleration. These physical properties don't actually have anything to say about their underlying nature.
Panpsychists say that, perhaps, consciousness is what things are. Consciousness is the intrinsic nature of all things. Rather than being a "small part of the vast universe, residing in the central nervous systems of living things ... the panpsychist claims that consciousness is everywhere".3 Down to the smallest components of the material world, everything has some capacity for experience, no matter how simple.
And then they sort of stop. Panpsychists are basically agnostic on what this might mean. No one really broaches the subject of what it might mean for an atom to have experience in some unimaginably tiny form. No one has ideas about how all these smaller capacities for experience coalesce into the complex form we experience day to day. It's the very same gap we were left with before.
The difference is more subtle. Materialists have this problem of explaining something qualitative with tools that don't seem capable of touching it. There's no scientific experiment one could run to explore experience stuff, for the same reason you'll never know if someone else sees red in the same way that you do. Non-materialists have this problem of explaining something we have no particular basis for. Where and how does non-material stuff exist? Where and how does it manifest? Where and how does it make its cross-over to the material plane? Panpsychists are simply pointing to another gap that no one has explored and saying, "well maybe it's happening somewhere over here".
So, we're no closer to some concept of universal consciousness. We're no closer to understanding the human experience (or, you know, any experience). In fact, if anything, we are reminded once again of just how limited our tools to explore the world really are. But, I suppose, at least we have somewhere new to look.