What are the greatest enemies to health and wholeness? If you asked most people, you would probably get obvious answers such as disease, or accident and injury, or perhaps old age and decrepitude. Some might suggest environmental degradation and pollution. Some might suggest alcohol or drugs. Someone might even mention the wages of sin and the potentially devastating influence of sinful actions.
If you turned to the textbook of Christian Science, however, you would get an answer that might at first seem startling. Christian Science doesn't casually dismiss people's common concerns. Yet instead of pointing to physical causes and their effects as fundamental, Science and Health with Key to the Scriptures by Mary Baker Eddy makes clear that we must primarily consider the mental factors that would war against humanity's health and well-being. Specifically, Science and Health states, "Mortal mind is the worst foe of the body ...."Science and Health, p. 176 .
Mortal mind is the enemy? What is "mortal mind," and why is it to be guarded against as "the worst foe"? If you were to suppose that there could be a limited mind—a mentality that held evil as real, that believed matter was the underlying substance of reality and thereby objectified such belief in finite and mortal forms, one that also suggested many separate, conflicting mentalities, that projected countless fears and sins, and that claimed to oppose God and work contrary to His will —you would have a basic description of much of what Christian Science classifies as "mortal mind." And because this mortal mentality would claim to proceed counter to God, good, it would also claim to be the producer not only of the predisposing conditions for disease and debility but also of the immediate circumstances that would make one sick or cause injury to the body. Many thinkers today are drawing similar conclusions regarding the mental causes of human disharmony.