Yes, thats definitely a key point: people are not rational creatures, but emotional. The rest of the book is just about ways you can tap into or get around that.

Another key point of the book is to let your counterpart talk as much as possible, while you listen. Really listen. Again, the techniques discussed are tools to help with that.

Everything else is sbout calming the person down, making them feel understood and heard, and unearthing what it is they actually value.