Whether dulness of sense is a sin distinct from blindness of mind?

❌ Objection 1 : It seems that dulness of sense is not a distinct sin from blindness of mind. Because one thing has one contrary. Now dulness is opposed to the gift of understanding, according to Gregory (Moral. ii, 49); and so is blindness of mind, since understanding denotes a principle of sight. Therefore dulness of sense is the same as blindness of mind.

❌ Objection 2 : Further, Gregory (Moral. xxxi, 45) in speaking of dulness describes it as "dullness of sense in respect of understanding." Now dulness of sense in respect of understanding seems to be the same as a defect in understanding, which pertains to blindness of mind. Therefore dulness of sense is the same as blindness of mind.

❌ Objection 3 : Further, if they differ at all, it seems to be chiefly in the fact that blindness of mind is voluntary, as stated above (Article [1]), while dulness of sense is a natural defect. But a natural defect is not a sin: so that, accordingly, dulness of sense would not be a sin, which is contrary to what Gregory says (Moral. xxxi, 45), where he reckons it among the sins arising from gluttony.