It’s been too long since I’ve written an installment of the series on faulty logic. It’s time to continue it, with...
Appeal to Popularity
There was a time when pretty much everyone thought that the Earth was flat. There was a time when anyone who thought about it was sure the sun went around the Earth. Come to mention it, there was a time when that was widely attributed to its having a ride on Apollo’s chariot. These were popular ideas.
But an idea’s popularity doesn’t make it right; it only makes it popular.
Of course, we use popularity to sell products all the time. “Mr Coffee is the best-selling drip coffee maker,” was presented to us as a reason to buy Mr Coffee. We’re urged to buy the best-selling aspirin and the most popular car, and to shop “Where America Shops.”
And an argument we often hear for the existence of God is that most people believe it. “Billions of people can’t be wrong.”
Well, yes, they can. Popularity doesn’t imply truth. We’ve spent a lot if time believing popular things, favouring popular things, supporting popular things... until they were no longer popular.
Now, we may, indeed, infer something useful from popularity when it comes to buying products. A brand might be the most popular because it really is the best. Then, again, the popularity could be due to good marketing and wide distribution and availability. It’s most useful to look at why it’s the best-selling pasta sauce or the most popular brand of cat food.
With scientific issues and the like, there’s also some value in considering “popularity”, but, here, in a different sense: where do the experts stand, who have studied the subject and know it intimately? In this case we’re not applying faulty logic, through appeal to popularity, but, as in the appeal to authority discussion, we’re looking to appropriate experts for their expert opinions.
Likewise, we could get the opinions of trained, expert food tasters for opinions on the best brands of food. We might poll those who prepare coffee professionally for their thoughts on the best coffee makers.
But our experts still need to have some sort of data behind their opinions, and we have to be careful in how we choose. Who, for instance, might we go to for expert opinions on God? One’s very assertion of oneself as an expert presupposes God’s existence. Experts in astrology, homeopathy, and feng shui are fine if you think these things are real and are looking for advice on that basis. But they won’t do us any good for studying the validity of the basic assumptions, and then we go back to the fallacy that popularity implies truth.
Appeal to Popularity: Just because a lot of people think something’s true, doesn’t make it so.
 Contrast this with study of religion itself, where one certainly can be a scholar on religious beliefs, cultural aspects of religion, and so on, independent of any such presupposition.