For with the simple prescription of diet, water, air and light the Natural Healer cures all diseases, of whatever standing, provided they are curable; for this method of treatment requires that there should be sufficient vitality of the body to enable a reaction to follow and the crisis to be got over.
The above-mentioned four fundamental healing factors remain constant, but the forms of their application vary infinitely in their succession and gradation. And what does the Natural Healer require of his patients?
Nothing but absolute confidence in his method, the only correct one, unswerving obedience to his instructions and a firm will.
If the patient possesses these qualities, the Natural Healer can generally guarantee a perfect cure.
SOURCE: The Natural method of healing, Volume 1 By Friedrich Eduard Bilz