32. We will also say how faith is formed from charity. Every man has a natural mind and a spiritual mind: a natural mind for the world, and a spiritual mind for heaven. In respect to his understanding, man is in both minds, but not in respect to his will, until he shuns and is averse to evils as sins. When he does this his spiritual mind is opened in respect to the will also; and when it has been opened there inflows from it into the natural mind spiritual heat from heaven (which heat in its essence is charity), and gives life to the knowledges of truth and good in the natural mind, and out of them it forms faith. The case here is just as it is with a tree, which does not receive any vegetative life until heat inflows from the sun, and conjoins itself with the light, as takes place in spring time. There is also a full parallelism between the quickening of man with life and the growing of a tree, in this respect, that the latter is effected by the heat of this world, and the former by the heat of heaven. It is for this reason also that man is so often likened by the Lord to a tree.