First, try listening to understand. (Not listen to respond.)
Second, ask for clarification/expansion of ideas that don't make sense.
Third, step back and consider
a - conditions that might make what the person is saying true
b - soft factors (where they're coming from).
c - if it is a workable premise within it's own parameters* (This is different than the fifth step)
d - is it consistent with the ideals of a group**
Fourth, the Machiavelli Factor
a - what they aren't telling you
b - possible whys they are telling you (what profit, positioning and motive)
c - the nature of how they are telling (insulting, conversationally, etc)
d - what they want you to do about the information (including nothing, but also deliberately not stopping them for future behaviors).
Fifth, then you start looking at if the idea is plausible given external factors.
a - are there other factors influencing the subject? (For example: Standard business practices are _______. )
b - are these factors a more plausible explanation? How do they influence? (For example how do crime, a higher number of uninsured drivers, more stoned drivers influence insurance rates?)
c - do these different positions have a degree of interconnectiveness (Can it be a combo of A and B?)
e - is the person dismissing other factors? (Basically claiming "NO! It's all about A!")
f - seek to find actual reasons why such an interpretation doesn't stand up, it's a whole lot more than an emotional "You're wrong."***
Sixth, ask if this person is aware of these other factors or bring them up in a non-confrontational manner. ("Are you factoring in _____")
Seventh, if you must refute the position: Make it about the position, NOT about the person. (Know this courtesy will often not be returned.)
Eight, know that certain canned doctrines are both very predictable in how they are presented AND the holes are consistent. When you derail those who are parroting, expect hostility. The faster they resort to that, the more you know you've got a Kool-Aid drinker. (No matter how much they pretend to be educated, informed and 'reasonable' about the subject.)
Nine, if someone comes up with some solid points that refute your position, consider them. It might just change your mind.
Running the early steps will get you thinking rather than just reacting emotionally and from pre-existing biases. It also helps to keep you from going tribal and protecting the ideology of 'us' against the evils of 'them.' (But at the same time, you'll be able to spot when someone is coming at you from a position of 'you're one of them!')
*Basically, without including external factors, does it make sense? (As opposed to "_______ exists because it's part of the Gray Lizard Men's conspiracy.")
** Does the idea stand up to the bigger ideas espoused by an ideology, or is this a perversion of those? (e.g., Christianity vs. the Inquisition)
*** At best, ‘you're wrong’ turns it into a debate (you're trying to win) vs. a dialectic (discussing different viewpoints to gain understanding). Far more common it just devolves into an argument, attitude and insults.