"I disapprove what you say, but I will defend to the death your right to say it."
This means that despite the person not agreeing upon what the other indiviudal has stated, they will fight to allow the person to maintain the right. This may link the right of freedom of speech which enables all individuals to speak their opinion despite it going against others or what they believe. For example, you may disapprove of the president and are guaranteed the right to express your distate for it, regardless if the president takes offense of it or not.