Author Terry Pratchett wrote a very moving article about 'assisted suicide' (a term he objects to) procedures in the UK, in light of his own condition. It's not terribly long, and like most of his writing, worth your time:
"Life is easy and cheap to make. But the things we add to it, such as pride, self-respect and human dignity, are worthy of preservation, too, and these can be lost in a fetish for life at any cost."
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