Language is definitely the most self-important part of the mind, and the only part proclaiming itself as "indispensable". The voice in our heads is most definitely telling us "if I wasn't here saying these things you'd be dead by now."
The math part of your brain never shouts equations at you to guilt and cow you into submission to do things you otherwise wouldn't or forego opportunities to quell the demons within. We also never consider that losing another faculty would "completely stop our ability to function", but we do think that about language. This article proves otherwise (its just another function, like math or the ability to do spatial reasoning).
> The math part of your brain never shouts equations at you
I'm not so sure. When I don't understand something, often mathematical or related concepts, that I want to understand, sometimes it won't let me go. And I wouldn't say that all my internal "calculations" on the topic can be distilled into thoughts.. in fact, that's why I don't understand it. There are symbols "shouting" at me to form a relationship that I don't fully grasp yet. They are more like images, but non-visual.. they don't yet fall into semantic categories that allow me to express them until I understand them, or you could say that when I learn to express them they take on semantic categories. Either way, non-verbal thoughts definitely occupy unexpected parts of my concentration at pretty regular intervals. Not sure that counts as "shouting" but it's maybe similar.
The sex drive is the most self-important part of the mind. It's the only part proclaiming itself as "indispensable". The feeling in our pants is definitely signalling to us "if I wasn't here feeling these urges our species would be dead by now."
There's still generic variation to the point where for some people this isn't a drive. Sure, it's a trait which self-selects itself for removal, but it's likely polygenic, which means it is much more likely that it can persist across generations despite being selected against. A lot of these things are non-intuitive, like how altruism can persist across generations despite being similar.
The math part of your brain never shouts equations at you to guilt and cow you into submission to do things you otherwise wouldn't or forego opportunities to quell the demons within. We also never consider that losing another faculty would "completely stop our ability to function", but we do think that about language. This article proves otherwise (its just another function, like math or the ability to do spatial reasoning).