If I said “1 + 2 = 3”, and you said “no, you’re wrong, 10 + 20 = 30”, are we disagreeing about anything?
We agree on the definition of “+” and we accept the magnitude of all the input numbers. We just happened to use different inputs and that’s why one answer is “3” and the other is “30”.
The basic principle behind “internal consistency” is that the conclusion (3 or 30) is logically deduced from the inputs and their operations (1+2 or 10+20). Both are “right” in their own abstract vacuum.
But if that same conversation happened in front of a table with 1 orange and 2 apples, one statement actually helps you figure out the # of fruit on the table.
It wouldn’t make sense to say, “no there’s actually 30 fruits on the table because 10 + 20 = 30”.
That’s an issue of “external consistency”; whether or not the claim properly represents the reality of nature (1 orange + 2 apples = 3 fruits).
Of course, life is simple when you’re counting fruit on a table. But if you ever feel like you’re shouting past someone and they’re “just not getting it”, it’s probably because you’re both “internally consistent” and you’re actually disagreeing on a matter of “external consistency”.
Something I’ve found often in work is that when someone disagrees, they’re actually pretty logical people. The issue is that we’re coming from different perspectives and so we aren’t agreeing on the same underlying premises.
It’s actually hard sometimes when you’re making a decision to know if the state of the world is “1” & “2” or “10” & “20”, or whether you should add rather than multiply.
At the very least, accepting that the other person is not an idiot (nor yourself) goes a long way towards figuring out what are their underlying premises & how they’re choosing to prioritize certain factors over others1.
This also comes up in the way I respond to most opinions: “sure, that’s internally consistent”.
It’s not meant as an insult. It’s meant as a: “let’s agree to disagree because I walked through your logic & I don’t see anything wrong with it, but I probably wouldn’t have started with your assumptions”2.
It also means that being “right”, in the sense that it’s internally consistent, is not really the bar for a good take. For example, when you call a take “reductionist”, you’re literally not calling it “wrong”, but you’re still calling it unhelpful.
Most conclusions can become internally consistent with minimal logical effort. The issue is whether or not using that conclusion actually provides a better lens to a problem, or whether you can apply that belief in a materially positive way.
So all that to say… don’t take me that seriously, it’s all internally consistent.
Occasionally this is frustrating because some people are not aware of their implicit assumptions.
Depending on the topic, maybe you can have them re-evaluate certain assumptions, but for the most part, all you can really ask for is for someone to be internally consistent.