Analogies have persuasive power, a suggestive force that operates on an almost unconscious level. To say that A is "like" B is to suggest that everything we associate with A should also be associated with B—whether good, bad, or ugly.
So, for example, if I describe American soldiers as "crusaders," I have just painted them with an analogical brush that colors them as religiously motivated warriors guilty of the worst bigotries of the West. The analogy is loaded with a moral depiction that exceeds what's actually said. So all the disdain we have towards our (usually caricatured) understanding of the Crusades is now overlaid on our perception of military operations in Iraq or Afghanistan.
Conversely, if I describe the proponents of my cause as "prophets" or "martyrs," I have loaded the perceptual deck with images of heroism and purity. Just by the analogy, we get to don our white hats and claim the moral high ground. Or if we describe our regime as "Camelot," we associate ourselves with romance and royal privilege. Never underestimate the power of an analogy. And never simply accept it.
We are all Galileans now
There is a particular analogy often invoked in current discussions about the relationship between Christian faith and science. Ours, we are told, is a "Galilean" moment: a critical time in history when new findings in the natural sciences threaten to topple fundamental Christian beliefs, just as Galileo's proposed heliocentrism rocked the ecclesiastical establishment of his day. This parallel is usually invoked in the context of genetic, evolutionary, and archaeological evidence about human origins that challenges traditional Christian ...