157. Every angel undergoes and passes through such changes of state, and also every society in general, and yet each one differently, for the reason that they differ in love and wisdom, those in the middle being in a more perfect state than those round about even to the circumference (see above, n. 43, 128). But it would be tedious to specify the differences, since the changes each one undergoes are in accord with the quality of his love and faith. From this it happens that while one may be in clearness and delight another may be in obscurity and lack of delight, and this at the same time within the same society. So, too, the state differs in different societies; it is different in the societies of the celestial kingdom from what it is in those of the spiritual kingdom. These differences in the changes of state are in general like the variations of the states of days in different climates on the earth, for with some it is morning when with others it is evening, and with some it is hot when with others it is cold. 158. I have been taught from heaven why there are such changes of state there. The angels said that there are many reasons-first, the delight of life and of heaven, which they have from love and wisdom from the Lord, would gradually lose its value if they were in it continually, as happens with those that are in allurements and pleasures without variety. A second reason is that angels, as well as men, have what is their own [proprium], which is loving self; and all that are in heaven are withheld from what is their own, and so far as they are withheld from it by the Lord are in love and wisdom; but so far as they are not withheld they are in the love of self; and because everyone loves what is his own and is drawn by it{1} they have changes of state or successive alternations. A third reason is that they are in this way perfected, for they thus become accustomed to being held in love to the Lord and withheld from love of self; also that by alternations between delight and lack of delight the perception and sense of good becomes more exquisite.{2} The angels added that their changes of state are not caused by the Lord, since the Lord as a sun is unceasingly flowing in with heat and light, that is, with love and wisdom; but the cause is in themselves, in that they love what is their own, and this continually leads them away. This was illustrated by comparison with the sun of the world, that the cause of the changes of state of heat and cold and of light and shade, year by year and day by day, is not in that sun, since it stands unchanged, but the cause is in the earth. {Footnote 1} Man's own [proprium] is loving self (n. 694, 731, 4317, 5660). The Lord cannot be present unless what is man's own is set aside (n. 1023, 1044). It is actually set aside when one is held in good by the Lord (n. 9334-9336, 9447, 9452-9454, 9938).