Consciousness

[Disagreeable]

First, the word "radical" is apparently meaningless in this assertion.  Consciousness is not some separate substance.  It is an evolved brain function.

So if there is only one kind of substance, then is that substance conscious or non-conscious?

Second, the assertion "There can be no emergence" is contradicted by the evidence.

We only have evidence of the experiential.

For instance, life emerged from complex combinations of non-living matter.  None of the elements which make up our bodies are alive by themselves.

But life can be explained in terms of non living parts. But subjective experience can't be explained in terms of non-subjective experience. Life from non-life isn't radical in terms of its emergence. Consciousness from non-consciousness is radical.

Does that mean all non-living matter is really living?  No it obviously does not.

Again, we can explain life in terms of things that are not alive. But we can't explain consciousness in terms of things that are not conscious.

Consciousness emerges from life, not directly from non-living matter.  Non-living matter has no use for consciousness at all.

Life doesn't have a use for consciousness either. We could react as if we were in pain, for instance, without actually having to feel it.

Consciousness emerges from non-consciousness every time we wake from deep sleep, a coma, or an anesthetic.

The consciousness emerges from the brain which is consciousness-involving. And just because we don't remember being conscious isn't evidence that we weren't or aren't conscious.

P1) Everything is physical
...
C4)  Therefore, Panpsychism is true

Your conclusion contradicts your premise; therefore, you've done something wrong.

That's not a contradiction. Under monism there is one kind of stuff and there is nothing stopping that stuff from being both physical and mental. Galen Strawson is an example of a panpsychist physicalist.