602. But it must be understood that while man may rise as to his understanding almost into the light in which the angels of heaven are, unless he rises also as to his will, he is still the old and not a new man. But it has been shown already how the understanding elevates the will more and more to the same height with itself. For this reason regeneration is predicated primarily of the will, and secondarily of the understanding. For the understanding in man is like light in the world, and the will is like the heat there; and it is known that light without heat does not vivify or cause vegetation, but light joined with heat. Moreover, as to the lower region of the mind, the understanding is actually in the light of the world, while as to the higher region it is in the light of heaven; consequently if the will is not raised from the lower region into the higher, and there conjoined with the understanding, it remains in the world; and then the understanding flies upward and downward, but returns every night to the will below and sleeps there; and they unite like a man and a harlot, and beget two-headed offspring. From all this it is clear that unless a man has a new will and a new understanding, he is not regenerated.