Thirteenth Rule. To be right in everything, we ought always to hold that the white which I see, is black, if the Hierarchical Church so decides it, believing that between Christ our Lord, the Bridegroom, and the Church, His Bride, there is the same Spirit which governs and directs us for the salvation of our souls. Because by the same Spirit and our Lord Who gave the ten Commandments, our holy Mother the Church is directed and governed. (emphasis added)
What occasioned this rule was likely the objection, common among 16th-19th c. Protestants, to the Catholic doctrine of transubstantiation, to the effect that we are more sure, on the basis of sense perception, that the consecrated wafer is just a wafer, than we are (based on Church testimony) that it is really the body of Jesus. God wants us, they would urge, to trust the senses he gave us, and believable miracle-claims let us do this.
I don’t see this sort of objection nowadays. I’m not sure why it went out of style. In any case, Loyola’s answer is clear – tradition ought to trump even a clear, close-up sensory perception. One would think, then, that it would also trump a strong intuition of falsehood – as when a set of claims appears self-inconsistent.
But even Loyola’s sense claim seems unreasonable. Suppose, contrary to fact, that Mother Church had long, strongly asserted that uneaten, consecrated wafers never rot. Then, you’re cleaning up the church, and find a wafer than you remember the priest dropping during Mass some months ago. It is rotten – covered with bread mold. You can feel, smell, and see the rot. Surely, you can (and will) reasonably believe that the wafer is rotten.