I've observed if I say nothing (because I simply don't know how to react), opinionated people think you agree with them, which I don't. I don't care.
what I want to tell him, next time he starts ranting: 'I don't care what you think, leave me alone'.
However, I may have to work with this person in the future, so what about 'you don't have to tell me everything you think, most of the time I don't pay attention' and if he keeps pushing it 'it's tiring working with a person who has to rant to feel good, it's boring and makes me ignore you, which is a problem, because we work together.' And leave.
What about 'everybody has problems, maybe talk to a therapist? I cannot help you'.
Unless you want to push back (clearly you don't), I wouldn't even acknowledge the topic or what about the topic makes you uncomfortable
"Hey man, this is a bar conversation. I don't feel comfortable talking about stuff like this at work."
I work in the same office as my best friend and I've told him similar - even though our politics are very closely aligned. Yes, I agree it would be funny if Trump shit his pants when he falls asleep in court. But I don't want people to hear us talking about that
When poeple went on political rants at work I would say "let's play a game. It's called Don't Talk Politics at Work. I'll go first!" Then I would shut up, turn around and keep on working. Just replace politics with whatever. It's low key funny with a deadpan delivery so I've never had anyone get mad at me for it.
There's two kinds of issues: instance and pattern. The first time or two, it's instance. You deal with those with specificity. Something like, "I would prefer not to talk about this subject with you, please stop".
If it persists, then it's a pattern problem. You deal with the pattern, not the instance. "I've asked you not to talk about subjects like this in the pant, but you haven't stopped. This makes me feel like you don't respect my boundaries and it's making it difficult for me to work with you. Why are you doing this to me?".
You can escalate from there, and this might involve management involvement but at least you'll have the clarity of having made the situation clear before it gets there.
Honestly though, unless the coworker is actually deranged, they'll be mortified when they find out they are making you uncomfortable and they'll stop right away.
Just pause awkwardly for a second, long enough to be felt but not long enough for them to start talking again, and bring up something unrelated
It'll hit them with the feeling of social rejection, but without the confrontation or giving them anything to latch onto. Nothing to get offended about or argue against, there's nothing to react to there
It might take longer, but it's not a request to stop - it's training them to not bring it up. It'll make them uncomfortable to talk about it - even if they force themselves it'll be uncomfortable for them
(Unless they're high on the spectrum, in which case direct is better all around)
Mastery of the art of awkward, is to invoke it as a means of protection for absurdity & curiosity tend to be the only defense against campaigns of idiocracy
I'm sorry[.] I can't be the good listener you want when it comes to this/these topics [at work]. I know you're very interested in this/them, and I value our relationship as colleagues. I can't think about this stuff at work, so I'd really rather we stop talking about it/them, please.
This is not necessarily effective on its own, but it's a way to find out what the situation is. It is a simple way to open the discussion about your lack of interest in what they have to say. Sometimes they just shut up.
I have a very similar problem but in my case the coworker is my boss. I have basically had to tell him he is wrong and that nothing he is going to say to me is going to change my mind and that I want no more of that conversation, I then change it to something work related. Sadly this has become the new normal. Thankfully my boss is expected to retire in December so I just need to wait it out.
My coworkers tell me that I am the hero of the group for shutting the boss down in such a loud and aggressive way. But its so exhausting.
Not if every time they start up you start talking about fossil species.
"You see what they are up to now?"
"That's a good question. Personally I am a fan of Cambrian, but who can deny how good the Permian was. Sure, the Jurassic had all the dinosaurs, but stuff Radiodonts and Hallucigenia are just so cool."
That's why I said be repetitive. It takes time. When they learn that all you do is go off on a tangent, they'll stop trying to use you for their personal sounding board.
In a way, you're responding to them in kind by reframing the convo to a subject in which they aren't interested.
You wanna be insensitive to others, and ignore the social cues that other's aren't interested just so you can selfishly rant? OK, I'll do the same, only with a subject that isn't divisive or inappropriate.
When all they ever get from you is utterly unrelated, they'll stop.
Or just change the subject completely, don't even acknowledge what they said, or make it really ridiculous. Like they talk politics, say" yea, my dog does this weird thing when politicians come on the tv" then tell a long, meaning, drawn-out, meaningless, made-up story about your non-existent dog.
Or "I don't really know anything about it, and don't really care to. Hey have you seen that email about vacation?"
Its hard to say without knowing your restrictions at work. In an open office I would grab my laptop and go work somewhere else. I assume you can't do that? If I could not do that can I wear headphones and listen to music while I work? If not that can I wear ear plugs? I find ear plug ignoring the person becomes aware you really can't hear them and eventually they try to get your attention then you pull it out and say sorry you use these to help your concentration. im not sure after that this is a social situation that you sorta figure out as you are there so all I got is possible physical space hacks. Oh if you have any phone calls or meetings always apologize and say your coworker talks a lot.