Quote Originally Posted by Philosopher8659 View Post
The human mind is one such system. It performs its task via language, both branches. If it cannot, then by definition of the above, it cannot contribute life to the organism, i.e. the organism dies. And if you look over the systems, death often is not immediate.

So by definition, if we cannot think correctly we are dead. If you understand the defining characteristic of the human mind, it deals with the future, death then awaits man.
It doesn't require much thought to survive, at least in the societies we all live in. It requires thought to hunt, grow food, cook, etc. Those things, if we were wild, or even now to an extent, help our survival. But I doubt that these days someone with an IQ of 130 will be expected to live much longer than someone with an IQ of 100. Someone who has mastered language, thought, etc. won't live longer than someone who hasn't.