455. That which has now been said can be understood by the rational man, for he can see it from the connection of causes and from truths in their order; but it is not understood by a man who is not rational, and for several reasons, the chief of which is that he has no desire to understand it because it is opposed to the falsities that he has made his truths; and he that is unwilling to understand for this reason has closed to his rational faculty the way to heaven, although that way can still be opened whenever the will's resistance ceases (see above, n. 424). That man is able to understand truths and be rational whenever he so wishes has been made clear to me by much experience. Evil spirits that have become irrational in the world by rejecting the Divine and the truths of the church, and confirming themselves against them, have frequently been turned by Divine power towards those who were in the light of truth, and they then comprehended all things as the angels did, and acknowledged them to be true, and also that they comprehended them all. But the moment these spirits relapsed into themselves, and turned back to the love of their will, they had no comprehension of truths and affirmed the opposite.  I have also heard certain dwellers in hell saying that they knew and perceived that which they did to be evil and that which they thought to be false; but that they were unable to resist the delight of their love, that is, their will, and that it is their will that drives their thought to see evil as good and falsity as truth. Evidently, then, those that are in falsity from evil have the ability to understand and be rational, but have no wish to; and they have no wish to for the reason that they have loved falsities more than truths, because these agree with the evils in which they are. To love and to will is the same thing, for what a man wills he loves, and what he loves he wills.  Because the state of men is such that they are able to understand truths if they wish to, I have been permitted to confirm spiritual truths, which are truths of heaven and the church, even by reasonings, and this in order that the falsities by which the rational mind in many has been closed up may be dispersed by reasonings, and thus the eye may perhaps in some degree be opened; for to confirm spiritual goods by reasonings is permitted to all that are in truths. Who could ever understand the Word from the sense of its letter, unless he saw from an enlightened reason the truths it contains? Is not this the source of so many heresies from the same Word?#
# The truths of doctrine of the church derived from the Word must be the starting-point, and these must first be acknowledged, and afterwards it is permissible to consult knowledges (n. 6047).
Thus it is permissible for those that are in an affirmative state towards the truths of faith to confirm them rationally by knowledges, but it is not permissible for those who are in a negative state (n. 2568, 2588, 4760, 6047).
It is in accordance with Divine order to enter rationally from spiritual truths into knowledges, which are natural truths, but not to enter from the latter into the former, because spiritual influx into natural things is possible, but not natural or physical influx into spiritual things (n. 3219, 5119, 5259, 5427, 5428, 5478, 6322, 9109, 9110).