A path controls the process. He didn't call it a piece of paper. The magisterium is supposed to produce perfect and infallible moral truth. The concept of purifying reality is mindless. What human minds do is acquire knowledge through applications of reason.
Knowledge increases incrementally by building one element upon another.
Correct reality gradually replaces incorrect reality. Thereby, knowledge evolves, as all realities evolve. Truth evolves, technology evolves, biology evolves, social institutions and standards evolve. If purified reality could be conceptualized at all, it would be a hypothetical end point, not anything in past tense. Pretending that there is a purified reality someplace defies the process of how reality is handled.