Those two categories are vague and non-exhaustive (and non-exclusive). Also, if the Ghostwriter writes his biography himself (entirely), in most senses of the w

Those two categories are vague and non-exhaustive (and non-exclusive). Also, if the Ghostwriter writes his biography himself (entirely), in most senses of the word, that doesn't mean he "helped" himself to do it. So, no paradox at all there, and certainly not a Russellian one.