An argument by analogy refers to an argument that makes inferences based on an analogy, or comparison, between two situations or objects.
False analogy, like the name suggests, is a logical fallacy in which someone argues on the basis of a faulty or weak analogy. It’s a common type of error as people frequently use misleading and inaccurate analogies to support their ideas and views.
It’s also known by a number of different names, including “weak analogy”, “false metaphor” and “faulty comparison”.
What Is a False Analogy?
The fallacy of false analogy arises when one attempts to prove or disprove a claim using an analogy that is not suitable for the situation.
It occurs either because one puts too much weight on the similarities, thus reasoning that the two cases being compared must be analogous in other respects too, or is unaware of the ways they are different.
As Anthony Weston pointed out in his book A Rulebook for Arguments:
Arguments by analogy…argue from one specific example to another, reasoning that because the two examples are alike in many ways, they are also alike in one further specific way.
As such, the success of an argument by analogy relies on the similarity and relevancy of the given example. Relevant analogies are effective tools for illustrating a point and can provide strong evidence for an argument.
However, if the cases being compared do not share enough similarities, or the similarities are not really relevant to the issue at hand, the analogy is too weak to be used justifiably.
One example of a faulty comparison is as follows:
- “A watch is a complex and precise device that is designed by an intelligent watchmaker. Similarly, the universe is an extremely complex system, and thus must be the product of intelligent design.”
This is fallacious because the conclusion is drawn from a few similar aspects between a watch and the universe, which are, in reality, more different from each other than alike.
This is more famously known as the “watchmaker” analogy, which is an argument formed by William Bailey (1802) for the existence of God.
- “You don’t believe in ghosts because you’ve never seen one? That doesn’t make any sense since you surely believe that molecules and black holes are a real thing, even
though you’ve never seen them with your own eyes.”
- “Telephones and bananas are shaped similarly, both fitting well to our hands. Therefore, just like the telephones have a designer, bananas must have a designer too.”
- “Cars cause many more deaths than firearms do, so if we are going to ban firearms, we should also ban cars.”
- “Many addictions, such as drug addiction or alcoholism, causes many people to destroy their health and eventually ruin their life. Thus, getting addicted to your phone will ruin your life.”
- “I think someone who can’t get up and running without having their morning coffee is as good as an alcoholic.”