284. Man's understanding is a recipient of both good and evil, and of both truth and falsity, but not his will, for this must be either in evil or in good; it cannot be in both, for the will is the man himself, and in it is his life's love. In the understanding, however, good and evil are separated, like what is internal and what is external. Hence man may be interiorly in evil and exteriorly in good; and yet while a man is being reformed good and evil are brought together, and then arise conflict and combat. This, if severe, is called temptation; but if not severe, what takes place is like the fermentation of wine or strong drink. If good then conquers, evil with its falsity is removed to the outskirts as, to use a comparison, the lees fall to the bottom of a vessel; and the good is like wine that becomes generous after fermentation and like strong drink that becomes clear. If, however, evil conquers then good with its truth is removed to the outskirts, and becomes turbid and noisome like unfermented wine and unfermented strong drink. This comparison is made with fermentation because leaven in the Word signifies the falsity of evil, as in Hosea vii. 4; Luke xii. 1; and elsewhere.