In the end, Voltaire decided that evil was eternal, but understanding where it came from was beyond human comprehension. The important thing, he said, "was not to understand its origins, but to confront it." His critics countered, "But if it is eternal, what difference does it make to challenge it?"
Voltaire said, "That was like weeds in a garden. To conclude that we should not pull them because we know they will come back would mean there could be no garden"' Voltaire said, "We must always tend the garden."
As Colin Powell leaves tonight on one more mission to try and broker a peace in the Middle East, a mission the administration at first resisted, we should remember the wisdom of Voltaire.
The question now is not who is right. In the Middle East, both sides are probably right. The question now is how to confront the killing and get it stopped.
The possibility of failure is real, but events are on the verge of spinning out of control. Radicals are now threatening the regimes of moderate Arab governments. The whole region could be set aflame.
Once again, the United States must tend the garden. We have little choice.
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By Bob Schieffer