To be explicit my P(#) is meant to be the Bayesian probability an observer gives to # being conscious, not the proposition P that # is conscious. It's meant to model Descartes's receptor, as well as disagreement of the kind, "My friend things week 28 fetuses are probably (~% 80%) conscious, and I think they're probably (~20%) not". P(week 28 fetuses) itself is not true or false.

I don't think it's incoherent to make probabilistic claims like this. It might be incoherent to make deeper claims about what laws given the distribution itself. Either way, what I think is interesting is that, if we also think there is such a thing as an amount of consciousness a thing can have, as in the panpsychic view, these two things create an inverse-square law of moral consideration that matches the shape of most people's intuitions oddly well.

For example: Let's say rock is probably not conscious, P(rock) < 1%. Even if it is, it doesn't seem like it would be very conscious. A low percentage of a low amount multiplies to a very low expected value, and that matches our intuitions about how much value to give rocks.