771. They who indulge the memory alone, or studies that are a matter of memorizing, or other studies but only for the sake of the memory, in the other life understand very little about what spiritual truth is, still less what heavenly truth is. They remain fixed in their own personal ideas, which form a kind of callus surrounding their brain like bone, or skull; and this callosity has first to be cast off, before truth can penetrate, and before spiritual and heavenly knowledge can have any abode. This callus is dispersed only with difficulty, and in fact, only with pain, or if perchance without these, then it has to soften, as it were, over a long period of time. Many experiences have shown this to me, and each time, the depiction of a callus amazed me.