similarly all good of love by reference to lesser good and to evil; all
truth of wisdom by a sense of lesser truth and of falsity. Everything
inevitably varies from greatest to least, and with the same variation in
its opposite and with equilibrium between them, there is contrast degree
by degree, and the perception and sensation of a thing increase or
diminish. But be it known that an opposite may either lower or exalt
perceptions and sensitivities. It lowers them when it mingles in and
exalts them when it does not mingle in, for which reason the Lord
separates good and evil with man that they shall not mingle, as
exquisitely as He does heaven and hell.

25. Conjunction of good and truth in others is provided by the Lord
through _purification_ in two ways; one through temptations, and the
other through fermentations. _Spiritual temptations_ are nothing else
than combats against the evils and falsities exhaled from hell and
affecting man. By these combats a man is purified from evils and
falsities, and good and truth are united in him. _Spiritual
fermentations_ take place in many ways, and in heaven as well as on
earth; but in the world it is not known what they are or how they come
about. For evils and their falsities, let into societies, act as ferments
do in meal or in must, separating the heterogeneous and conjoining the
homogeneous until there is clarity and purity. Such fermentations are
meant in the Lord's words:

The kingdom of heaven is like leaven which a woman took and hid in three
measures of meal until the whole was leavened (Mt 13:33; Lu 12:21).

26. The Lord provides these uses through the united evil and falsity of
those in hell. The Lord's kingdom, which extends over hell as well as
over heaven, is a kingdom of uses. It is the Lord's providence that there