I think the original post is missing something in writing off the word "merely". Any perceived entity may be fundamental or reducible (illusory would be one kind of reducible). It may be the case that something new is discovered by analysis - for example, the explanations of electricity, magnetism and the nature of light involved the new and unexpected electromagnetic field and the equations of Maxwell. On the other hand, explanations may "merely" involve things already known - for example, gamma rays turned out to be "merely" electromagnetic waves, and beta rays "merely" electrons (unlike alpha rays, which required new physics).

Personally I think awareness itself, and probably also volition, will require new physics. I'd certainly regard it as an unwarranted act of faith to assert that the known particles and forces, as of this moment in time, MUST be entirely sufficient to explain free will, intention, purpose, ethics, value and the rest.