Fallacy of analogy
The fallacy of analogy also called fallacy of comparison is a logical fallacy that argues that because one thing resembles another in some aspects, they must resemble each other in another aspect. In its most extreme form, it argues that a superficial resemblance proves identity, that they are in fact the same. In general, an argument by analogy takes the following form:
A is like B (they share properties X,Y, and Z).
B also has property Q
Therefore, A has property Q as well.
The strength of such an argument depends upon the strength of the analogy; it may actually be the case that A is not much like B at all. If A and B have more differences than shared properties, the argument is weakened. It may also be true that A is like B in many ways, but still differs from B in terms of the specific property Q. If the analogy is too weak or irrelevant to the conclusion that is drawn, then a fallacy of weak analogy has been committed. An analogy itself is never true or false; it is only weak or strong. Consider the following examples:
A tomato is like an apple.
Apples grow on trees.
Therefore, tomatoes grow on trees.
Here, the analogy between tomatoes and apples is weak; they may have similar size and color, but these similarities are superficial and there are many more ways in which they differ. Therefore, the conclusion is not well supported.
Mike and his twin Chris are the same height and weight, have similar jobs, identical political beliefs, are fans of the same sports teams, and attend the same church.
Mike is male.
Therefore, Chris is male also.
In this example, Mike and Chris may be virtually identical in almost all ways, and yet these similarities are not relevant to whether they are two brothers or brother and sister (also, Chris can be short for Christopher or for Christina).
Therefore, the erecting of statues is an act of idolatry.
This analogy is weak because it does not include the purpose of erecting statues that are not intended as idols.
But the similarity of the gospel story to the fictions of pagan myth does not mean that it is therefore just a made-up fairy tale or fable. No. The historical evidence for the essential facticity of the gospels is sound. The analogy of the Christian Gospel to the fictions of pagan mythology as proof that it is only a myth with no historical basis in reality is extremely weak.
Fallacious or weak analogies are frequently used in prejudiced accusations against ethnic groups, and in polemic against religions and religious practices, and by prosecutors in courts of law to persuade judges and juries of the guilt of the accused.
- "Man looketh on the outward appearance, but God looketh on the heart." 1 Samuel 16:7.
- Are the Gospels a Myth? by Fr. Dwight Longenecker (strangenotions.com)