That's a logical fallasy!

[robvalue]

For the benefit of puzzled bystanders, I think I have figured out what Cap'n was trying to say with one of his points.

I think he was saying that an argument containing a fallacy may still produce a valid conclusion if the conclusion is not dependent solely on the logical step in question.

It seemed we were talking at cross purposes with regard to this point. I was discussing a series of linear logical steps leading to a conclusion. Then if any one of those steps contains a fallacy, the conclusion to that argument has not been demonstrated to be true. But if several arguments have been put forward to make the point in question, then as long as they don't all contain fallacies, the point can still be made.

However, if done constructively and tactfully, it can still sometimes be beneficial to point out the fallacy if you think it would benefit the person. Critical thinkers usually like to know if they make mistakes. It's down to context, it may not be appropriate and may be just nit picking. Depends. Categorising errors can sometimes be useful as it helps the person see a possible general problem in their thinking which they can address, rather than just the specific example. Particularly if you see that person making the same mistake over and over. Again, contextually. I'm not advocating smearing fallacy labels willy nilly, or to someone who clearly doesn't appreciate thm.