In a broad general division, philosophy finds three causes of sickness. They are wrong thinking, wrong living, and bad karma. But because karma merely brings back to us the results of the other two, we may even limit the causes of disease to them. And again because conduct is ultimately the expression of thought, we may limit the cause of disease finally to a single one of wrong thinking. But this is to deal with the matter in a metaphysical, abstract, and ultimate way. It is best when dealing with sickness in a practical way to keep to the threefold analysis of possible causes. Yet the matter must not be oversimplified as certain schools of unorthodox healing have oversimplified it, for the thinking which produced the sickness may belong to the far past, to some earlier reincarnation, and not necessarily to the present one, or it may belong to the earlier years of the present incarnation. In those cases, there is the fruit of an unknown earlier sowing, not necessarily of a known present one. Therefore, it may not be enough merely to alter one's present mode of thought to insure the immediate obliteration of the sickness. If we shoot a bullet in the wrong direction, we cannot control its course once it has left the gun. But we can change the direction of a second shot if we realize our error. We can continue our efforts, however, to change our first thinking, to get rid of negative harmful thoughts and feelings and thus improve our character. For if we do this, the type of physical karma manifesting as the sickness which they create will at least not come to us in the future, even if we cannot avoid inheriting it in the present from our former lives. Study of this picture would reveal what sickness as a karma of wrong thinking really means and why it often cannot be healed by a mere change of present thought alone. The proof of this statement lies in the fact that some people are born with certain sicknesses or with liability to certain diseases, or else acquire them as infants or as children before they have even had the opportunity to think wrongly at all and while they are still in a state of youthful innocence and purity of thought. Therefore it is not the wrong thoughts of this present incarnation which could have brought on such sickness in their case. Nor can it be correct to suggest that they have inherited these sicknesses, for the parents may be right-thinking and high-living people. By depriving themselves of faith in the belief in successive lives on earth, the Christian Scientists deprive themselves of a more satisfactory explanation of the problem of sickness than the one they have. They say that it was caused by wrong thinking, and yet they cannot say how it is that a baby or a child has been thinking wrongly to have been born with or to have acquired at an early age a sickness for which it is not responsible and for which its parents are not responsible.
-- Notebooks Category 10: Healing of the Self > Chapter 3: The Origins of Illness > # 7
-- Perspectives > Chapter 10: Healing of the Self > # 4