[grandempire]

Take ad hominem. It’s true that there is no logical connection between who is saying something and whether it’s true.

But in practice, that’s one of the most relevant factors of whether you should be listening to someone. Does this person have a solid track record? Do they have your interest in mind?

So it is relevant information. It’s just that, “well once this guy kicked a dog” is usually done in bad faith.

So I wouldn’t consider it a non-sequitor, except in its most crude forms.

[taeric]

In this vein, one of the more insipid traps of these fallacies is that they do not lead to a conclusion, on their own.

Ad hominem continues to be a good example. If you know that someone is a liar, you don't know that everything they say is false. You just know that they lie and are likely saying something to affect listeners. Could be based on some truth. Could not.