a question

[benjpound]

the other climbers were all for giving up the attempt,
but it was............impossible to convince him of the need to do so.

a) too b) quite

first I chose "too" for the answer although I couldn't eliminate "quite" for why it isn't correct here.
Well, then it turned out that "quite " is the correct answer but I don't understand the logic behind it
although I have some hypothesis.

If I use "too" here it means I couldn't convince him.
If I use "quite" here it means I was able to convince him.
Am I right?
thanks for your answers in advance.

 

[benjpound]

A thing is either impossible or not ('quite' here means 'absolutely). A thing cannot be 'too' impossible, and more than somebody can be 'too dead'.

So we can't use too impossible" together.
Ok.Thank you.