As for terrestrial human beings, they have, through religions, wisdom and science together with the other phenomena of life itself in the last few centuries, gone through a rapidly accelerating process of evolution. This has in particular caused an outstanding development of intelligence in the individuals. This development of intelligence has widened their sensory horizon and given them mastery over forces or realities of which they had previously no notion. As this new mastery is, of course, the same as an increase of so-called "free will", this "free will" of the human being has thus been raised a little above the ordinary, habitual, primitive animal form of "free will". While this latter form of will is largely directed by an aptitude for instinct, the former form has now to a great extent gone over to being directed by an aptitude for intelligence. The terrestrial human being has thus to a certain extent raised himself above the ordinary animal kingdom by the conquering of extensive new spiritual or mental terrains. But to the same extent as the human being has in this way come into new spiritual areas, using intelligence instead of instinct, instinct of course degenerates; for it is an unbreakable law of Nature that those parts of an organism, such as organs, limbs, senses and so on, that are not used, finally become unusable and degenerate, to be completely dissolved at last through various following incarnations, and disappear; so they can be maintained absolutely only by being used. Since the animal's pre-eminent and developed instinct is thus degenerated in the human being, and this instinct was the basis for the ability to feel absolutely normal hunger and thirst, the terrestrial human being's ability to feel this is thus to a corresponding degree degenerated.
      If the terrestrial human being's organism had not been refined at the same time as he evolved out of the animal kingdom but had, on the contrary, continued to be equally robust, enabling him to consume the usual coarse animal food, then his habitual consciousness would have been able to save him, for there would not then have been any change in his way of living. But the organism is, as previously mentioned, refined; and correspondingly refined substances are demanded for its maintenance or existence. But, as the terrestrial human being in his evolution has thus come into areas where his organism can no longer tolerate to the same degree as before the old animal food but demands new and refined products for its nourishment, and as his instinct in these new areas is in a degenerated condition, so this instinct can no longer guarantee the individual's desire for or choice of the right food as in the old areas. And the individual must then with his intelligence seek to arrive at an understanding of which foodstuffs are the right ones for his organism's present step in evolution. But since nothing in the organism can be born fully grown but can become usable only through gradual development, so intelligence too cannot be born fully grown but must be developed. Since intelligence can be developed only through experiences, so the terrestrial human being must, in those areas where he has lifted himself beyond being led by the old animal instincts, learn from experience the true realities. But experience arises on the basis of error; so the terrestrial human being finds himself in a zone of evolution where he, precisely because of his failing instinct and his as yet lacking intelligence, makes an immeasurable number of mistakes. By virtue of his developed free will he can choose what he wants to eat and drink, but he has neither the instinct nor the intelligence to choose the absolutely perfect food or that food which is absolutely appropriate for his organism's evolutionary step. He therefore, to an exceptionally great extent, comes not only to choose foodstuffs that can only in a general sense be said to be foodstuffs but he even chooses realities that are absolutely not foodstuffs. Now, to take into an organism foodstuffs that are not appropriate to this organism creates disharmony in it. As disharmony in an organism can elicit only illness or pain, it is understandable that this has given rise, within terrestrial mankind, to such realities as "medicine men", "quacks", "wise men" and "wise women", "faith healers" and "doctors", all of whom constitute more or less successful repairers of undermined and overburdened organisms. Furthermore, it is the same circumstances that cause distressed mankind to cling to the innumerable "patent medicines" that flourish so prolifically, or to all kinds of powders and liquids, if only they have the label "medicine" stuck on them, quite regardless of how dangerous and undermining for the organism they are, according to cosmic analysis. Anaesthetics, which certainly relieve temporary pain but thereby in reality undermine the organism's recognition of the presence of these poisonous substances in the organism and its struggle or resistance to them, have likewise been discovered or invented. It is a matter of course that a form of life or existence that in the shape of unnatural food and drink so promotes a continuous accumulation of poisons within the organism and furthermore as "medicine" promotes another accumulation of poisons, which perhaps in certain cases can remedy the effects of the former (but on the other hand in many cases leave behind quite other harmful and incurable effects), finally undermines even the highest creative power of the individual or the "X2" referred to in "Livets Bog". According to eternal laws of love this undermining will culminate in a catastrophe. This catastrophe is admittedly terrible in itself, and appears as the very highest or most radical experience that exists, but, on the other hand, precisely by virtue of its strong effect, it stops total undermining and thereby brings the individual back to what is normal or natural with the will and the power never more within the present spiral of evolution to depart from the normal or divine ways within the area of nutrition.
      This catastrophe is thus elicited through the individual's having for a while completely lost his creative power and, in the worst cases, in many incarnations being thereby completely unable to create a perfect or normal physical body; he must therefore in such periods appear on the physical plane as a person whom we term "mentally handicapped". Here we must bear in mind that, according to "Livets Bog", the present physical appearance of the individual is determined by three sets of heredity in the form of innate talents or natural capacities – namely his own talents from a previous existence – and the talents or natural capacities of his father and mother, which to a certain extent are present in his physical body. While the natural capacities or tendencies of the father and mother to a certain extent dominate the individual during childhood, thereafter to decline up to the age of thirty, then the individual's own heredity or innate tendencies from a previous existence dominate his body from that age until and beyond death. And it is this inheritance from a previous existence that determines the normality of the individual's present physical incarnation. But this problem is too vast to be elucidated here, and for the study of this I must therefore refer the reader to my main work, "Livets Bog".