Bill Gates, the world’s richest man, has a plan: to eradicate malaria, a tropical, mosquito-borne parasite that causes fever, chills and in extreme cases, death. Epidemiologists, though, are skeptical of the short-term prospects of eliminating the parasites. They believe that funds could better be used on controlling the spread of the disease rather than eradicating it outright. Directing efforts at eliminating the disease entirely could draw funds away from proven methods of control, such as mosquito nets, pesticides, draining pools of standing water and DDT spraying. Malaria cases can be cut over 90% using these methods alone. “But eliminating the last 10 percent is a tremendous task and very expensive,” said Dr. Arata Kochi, malaria chief of the World Health Organization said. “Even places like South Africa should think twice before taking this path.”

The debate between controlling a disease or eliminating it entirely is not new. Since the dawn of human history, it has been our task to combat evil in various forms. Outward evils, such as sickness and natural disasters, are a reflection of our inner state. When Adam and Eve were in the Garden of Eden, they had not yet internalized evil, which presented itself in the form of a snake. Only by eating of the fruit did the evil become part of them. Ever since their banishment from the garden, as a result of their sin, we have been trying to undo the damage, by resisting our evil inclination and elevating our daily lives to holiness.

Our progress in the quest to eradicate evil has not been smooth, and there have been times when evil seemed to have won the upper hand. Then we rallied and fought off the evil again, so that it became dormant, until erupting at some later time. This corresponds to the concept of fighting disease by controlling its spread. We can work on resisting temptation, but we are susceptible as long as the evil still lurks, and can fall prey to it again.

Another approach, as advocated by Mr. Gates, is to eradicate the evil completely. How can that be done? Through immunization, the body never becomes susceptible to the invader. It has nowhere to go, so it becomes eradicated as a matter of course. This corresponds to a method of fighting evil through spreading light and strengthening the forces of good. If our spirit is healthy, we are not susceptible to the enticements of the evil inclination. Soon, the evil disappears on its own, just as dark naturally retreats before light, with no need for doing battle.

This will be the final state of the world in the Messianic Era, when G-d will “remove the spirit of impurity from the land.” We will decisively overcome all evil, not through battling it directly but by fortifying and immunizing ourselves through Torah study and good deeds. No evil will have an opportunity to take root and flourish, since the world will be filled with goodness and knowledge of G-d.

Prof. Yirmiyahu Branover is chairman of the Center of Magnetohydrodynamic Studies and Training at Ben-Gurion University.