According to panpsychism, mind is ubiquitous and fundamental. To support their position, contemporary panpsychists rely in part on what Michael Della Rocca calls an explicability argument — an argument in which “a certain state of affairs is said not to obtain simply because its obtaining would be inexplicable, a so-called brute fact.”
One reason that panpsychists reject the idea that consciousness is a strongly emergent property of certain functional or physical states, for example, is because strong emergence would be brute. If consciousness is strongly emergent, there is by definition no reason why consciousness should pop into existence when certain states are instantiated. Put the pieces — neurons, computer chips, beer cans — together in the right way, and then — poof! — all of a sudden, consciousness happens, and that’s the end of the explanation. According to the explicability argument, this gives us good reason to reject the claim that consciousness is strongly emergent.
But why stop there? If consciousness is neither reducible to nor strongly emergent from the physical, what explains why there is consciousness? The only remaining options seem to be that the existence of consciousness is a brute fact, or that consciousness necessarily exists. The explicability argument used to rule out strong emergence, however, also seems to rule out consciousness being a brute fact. This leaves three possibilities. Either explicability arguments are illegitimate, there is a principled reason to accept the explicability argument against strong emergence while rejecting the explicability argument against brute consciousness, or — most plausibly, I think — consciousness is a necessarily existent phenomenon.