42. It should also be known that there are three degrees of love and wisdom, and so three degrees of life; and the human mind is formed into three regions corresponding to these degrees. Life in the highest region is in its highest degree, in the second in a lesser degree, and in the last in the lowest degree. These regions are opened up successively as a person grows up. The last region, where life is in its lowest degree, is opened up from infancy to childhood, as different kinds of knowledge are acquired. The second degree, where life is in a greater degree, is opened up, from childhood to adolescence, as the result of thinking based on knowledge. The highest degree, where life is in its highest degree, is opened up from adolescence to early manhood and beyond; and this is brought about by grasping both moral and spiritual truths.
[2] It should further be known that perfection of life consists not in thought but in perceiving truth in the light of truth. From this one can deduce how different people's lives are. There are those who at once on hearing a truth perceive that it is true; these are represented in the spiritual world by eagles. There are those who do not perceive a truth, but deduce it as the result of arguments based upon appearances; these are represented by song-birds. There are those who believe a truth at the behest of an authoritative speaker; these are represented by magpies. There are also those who do not wish to and those who cannot perceive a truth, but only falsity. The reason is that they live in a deceptive light, and this makes a falsity look like truth, and a truth either as something overhead wrapped in thick cloud, or as a meteor, or even as falsity. Their thinking is represented by little owls and their speaking by screech-owls. Those of them who have convinced themselves of their false beliefs cannot bear to hear truths, and as soon as any truth knocks at the door of their ears, they turn away and reject it, very much as a stomach crammed with bilious matter is nauseated by food and vomits it up.