Centrists are so often frustrated with the black-and-white thinking of the Political Left and Right that I think it's worth reflecting on the useful role each political pole plays in the ecology of our political system.

Perhaps most importantly, the Left and Right wings supply much of the energy into the political system. While solutions may come about from compromise and persuasion, the movement toward resolution of problems is often sustained by pressure from one or the other political pole. It is much like the relationship between the Id and the Ego--the extremes supply the drive, the centrists find the solutions.

That formulation makes sense in terms of the routine operation of the government, but the more dramatic functions of the extremes are seen when societal paradigm shifts happen. Without a Left and a Right, we never would have seen either the civil rights movement of the 60s or the arrest in growth of the welfare state of the 80s-90s. The poles often supply the Big Ideas, or champion them before they have a chance to win general acceptance.

Finally, even if centrists had all the answers to the social and political problems of the day, unfortunately much of their impetus to action comes from a need to counter what they see as harmful initiatives by the political poles, and replace them with their own intitiatives. In this way, the Left and the Right prompt those in the Center to become politically active when they might otherwise not be.

So next time you're discussing abortion or Iraq with a liberal or conservative who just digs in his heels, try not to get too frustrated. He's chosen his role in the political ecology, and it's all just the circle of life.