Galen Strawson starts with the one fact of which we are most certain — our own consciousness:
He breaks his approach down into steps:
Step one is: one thing we know for sure is that consciousness is real.
Step two—this is an assumption, technically— [is] I believe there’s only one kind of stuff and I call it “physical stuff.”
So, I’m a physicalist and I know that consciousness is real. I have to say that consciousness is physical. That’s step three.
ROBERT WRIGHT, “WHAT IS IT LIKE TO BE AN ELECTRON? AN INTERVIEW WITH GALEN STRAWSON” AT NONZERO (JUNE 28, 2020)
But now what is Step four? If consciousness is physical, is it universal in both animate and inanimate nature?
Whether or not Strawson’s panpsychism offers a coherent view of evolution, it’s easy to see the attraction: a way of accommodating consciousness, the one thing of which we feel utterly certain, in a wholly material universe. Those who are content to make fun of panpsychism are probably underestimating that attraction.
Takehome: To Strawson, it makes more sense to say that consciousness is physical — and that electrons are conscious — than that consciousness is an illusion.
You may also wish to read: Why would a neuroscientist choose panpsychism over materialism? It seems to have come down to a choice between “nothing is conscious” and “everything is conscious.”