How much of a body can be amputated and survive?

Factual Questions
1

A question brought to mind “thanks” to #3 of this Cracked article.
The title pretty much says it all. How much of the human body can be amputated while leaving the body alive and the brain’s higher functions working, even if only with the help of current medical machines and treatments.
Since I’m looking for a (hopefully) theoretical answer; mods, please move if not right for GQ.

Thanks in advance - DESK

2

at least half

3

Thanks for the link, Cub Mistress. I hope Angel1366 isn’t offended or disturbed by my question. She’s the ultimate definition of survivor.
I mean my question to be theoretical only.

Peace - DESK

4

You can lose a surprising proportion of the head as long as the spinal cord and brain aren’t damaged. This video on Youtube shows a man in Syria in the recent uprisings who has has lost most of the lower part of his face, but is still perfectly conscious (watch out though - that video is extremely graphic).

5

Actually, you can lose a surprising amount of the brain and still function normally.