5937. What the perception is that is so often mentioned shall here be briefly stated. There is with every man a capacity of perceiving whether a thing is so or is not so. The capacity of drawing a conclusion within himself, or in his own mind, causes a thing to be perceived. This capacity is utterly impossible unless there is influx from the spiritual world. In this gift one man excels another. They who excel less are they who within themselves or in their own mind conclude and thus perceive but little; but say that a thing is so because others in whom they have faith have said so. But they who excel more are they who see, not from others, but from themselves, that the thing is so; for in very deed the perception which exists with every man is one in worldly things, but not at the present day with anyone in spiritual things. The reason is that the spiritual which flows in and causes perception has been obscured and almost extinguished by the delights of the love of the world and of self; and therefore neither do they care for spiritual things, except insofar as is of duty and of custom; and if fear from duty, and delight from custom, were taken away, they would spurn, feel aversion for, and even deny them.
 He who would have perception in spiritual things must be in the affection of truth from good, and must continually long to know truths. Thereby his intellectual is enlightened, and when the intellectual has been enlightened, then it is given him to perceive something inwardly within himself. But he who is not in the affection of truth, knows that which he knows to be so, from the teaching of the church to which he joins his faith, and because a priest, presbyter, or monk has said so. From all this it is evident what perception is, and that it exists in worldly things, but not in spiritual things; as is further evident from the fact that everyone remains in the doctrine in which he was born, even they who were born Jews, and also they who are outside the church, although they live within it. Moreover they who are in any heresy, if told the veriest truths, and if these were also confirmed, they would nevertheless perceive not one whit of their truth: they would appear to them as falsities.