The puzzle of why and how I so often find myself on two sides of a question is solved. I'm so often at war with myself because it is in my genes.
Doing research on my Civil War ancestors, I was surprised to discover I have family on both sides of the war. The famous "brother against brother" tragedy was literally true in one of my families, where half fought for the North and the other half fought for the South.
Going back to the Revolutionary War, I have so far found only American Patriots, but I wouldn't be surprised to discover some ancestors who stayed loyal to England.
Although two of the twenty-five barons standing for Magna Carta in 1215 were my direct ancestors, it turns out that one of my ancestors was standing on the other side of the dispute. King John's 'right-hand man', Sir William Marshall, stood by his side at Runneymede. Marshall is my 23xgr-grandfather.
Now I understand why I often argue "with myself" over a problem. It is an inherited talent.