Using popularity as a premise for an argument

[musicgold]

Hi,

In my mind, the following argument is a strong inductive argument, but according some experts it is a fallacy - appeal to popular opinion.

Lots of people bought this album, so it must be good.

In today's world,customer reviews and popularity rankings are commonly used tools to make a purchase decision. Are they all using poor logic? How should I think about this?

Thanks.

[Adam Tyson]

From a purely logical perspective, that is indeed bad logic. Popularity may be an indicator or something being good, but it is never proof that that thing is good. Maybe it's popular because of good marketing? Maybe because people have bad taste? Maybe because we are all just lemmings, following each other over a cliff of terrible stuff because we cannot think for ourselves? Or maybe, just maybe, it's popular because it's good.

This doesn't mean that you should never use popularity as a guide to helping you make decisions. In the real world, it makes sense to consider the possibility that the thing that everyone else seems to like may indeed be a thing that you would like. Ultimately, though, that popularity is just one piece of evidence, and it isn't conclusive. That's the fallacy - believing that popularity is enough to prove quality or truth. At one point most of the people in the world believed the world was flat, a very popular idea. That didn't make it true, though. Now, most people believe that it's round, but guess what? That popularity of belief does not, by itself, prove that the world is round! Other evidence, like photographs from space, measurements by surveyors, evidence provided by ships that have sailed in one direction and eventually found themselves back where they started rather than falling off an edge somewhere, has to be considered in addition to popular opinion.

So, at least on the LSAT, never ever take popular opinion as definitive proof of anything. The best you could say is that the album, in your example, MAY be good.

Hope that helps!

[musicgold]

Thank you.