The mutual distrust between Valley dwellers and Dalriadas thrives on ignorance and fear. It is easy to see the parallels with cultural and ethnic conflicts in our own world. For example, some early white settlers considered the Native Americans not human and justified bad treatment of them with this belief. Tensions between ethnic groups grow when people stay strictly in their own communities, basing their ideas about other groups on rumor and imagination. Likewise, more knowledge and interaction usually leads to understanding. As Americans have become more mobile, old prejudices between ethnic and religious groups have ebbed when people realize the things they have in common as citizens and human beings.

At the same time, there are real lifestyle and economic differences between Valley folk and the Dalriadas. Valley dwellers are farmers, and the Dalriadas cannot understand why people would spend their lives that way when...