Voltaire, whose birth name was Francois-Marie Arouet, is well-known for his defense of civil liberties and his ideas about human brotherhood. The quote that is most often connected to him has to do with this. That is the quote that goes
I disapprove of what you say, but I will defend to the death your right to say it.
However, it is clear that Voltaire himself never wrote or said this phrase. It is actually a statement of his values, but not one that he himself said.
One famous quote that is truly from Voltaire is also on the subject of civil liberties, religious toleration, and the universal brotherhood of human beings. Voltaire wrote
I say that we should regard all men as our brothers. What? The Turk my brother? The Chinaman my brother? The Jew? The Siam? Yes, without doubt; are we not all children of the same father and creatures of the same God?
This quote is not as well-known as the one that he didn't actually say, but it is a good representation of the sorts of things that Voltaire believed.