goodwill?
hi there
1.whats meaning of "goodwill "in this sentence.
2.and gist of this sentence."like knocking out color but nothing else."

You think, for
example, the whole world, full of color, and movement, and depth, and
meaning, is given to you. But it’s not. It is dependent on the goodwill
and the good functioning of forty or fifty different parts of the brain, all
linked together. And any one of these can go wrong and knock out a
single thing, like knocking out color but nothing else.

Question

goodwill?
hi there
1.whats meaning of "goodwill "in this sentence.
2.and gist of this sentence."like knocking out color but nothing else."

You think, for
example, the whole world, full of color, and movement, and depth, and
meaning, is given to you. But it’s not. It is dependent on the goodwill
and the good functioning of forty or fifty different parts of the brain, all
linked together. And any one of these can go wrong and knock out a
single thing, like knocking out color but nothing else.

Answer

Hello,
I believe that the word goodwill is used metaphorically here. Goodwill here means, the benevolence of the brain. Which means that if the different parts of the brain work together, and efficiently, like they are doing you a favor, only then will you be able to experience all these things (color, movement, depth, etc). 
If however, even one of the parts of the brain refuses to cooperate, then they 'knock out a single thing', which means that there is some sort of disability, in experiencing these things. Knocking out color but nothing less refers to perfect vision with color blindness. You can see, but cannot see color. SO the color blindness is the 'single thing'.

Answer

'Goodwill' means people doing good acts/actions towards you. E.g. Being nice and helping you with something.   
Knocking out color is a metaphor for describing how if something goes wrong in the brain (mentioned earlier in the text) it can make you blind or not let you see things clearly