The essay "Writing for the opponent" (also known as "Writing for the enemy") describes a process for fairly and neutrally explaining someone else's point of view, even when it disagrees with your own.
It is similar to the sentiments behind the expressions "playing the devil's advocate" or "walking in someone else's shoes". This process is helpful for writing Wikipedia articles and participating in discussions, both online and in real life. Understanding opposing positions reduces the "us vs. them" mentality and promotes a more civil discourse.
Quality Wikipedia articles present different viewpoints, with proper weight given relative to their significance, and are neutral in tone. Editors should describe topics without endorsing or disapproving of viewpoints, and they should include opposing perspectives in articles (or at least allow others to do so). Not including opposing points of view goes against Wikipedia's neutral point of view policy.