Critical Literacy . . . What?

Over this past week, I have been contemplating the definition of critical literacy? What is it exactly and what am I suppose to do with it? As a historian, I have to apply this concept to the field, but also to the view point of a teacher. What does that mean? I am not so sure. But what I do know is that this term applies to my classroom and my kids in an important way. People have speculated over the years about the definition of critical literacy, but to no avail. It is an every changing definition. Professor Vasquez assumes that this is a good thing. When a definition becomes concrete and unchanging, we loose the ability to really look, understand, and apply that concept.
As I see it in my small world view, critical literacy is when you are reading, listening, or watching a object and you step back for a second and reevaluate everything you know and understand about that object. When reading a primary source document, the words are there, but the emotions, events, and thoughts that are behind that document are often forgotten by the reader. At that point, one must take a step back and consider all the outside factors that went into the creation of this document. It is my responsibility as a teacher to do this with everything I pass out to my students, but also bring my students along on the journey. By having the students take a step back and reevaluate will hopefully bring a new perspective to the document. It is not simply words, these primary source documents were a part of someone and their life and it is important for us all to realize that their lives were as complicated as ours.
There are theories out there in the world of critical literacy that can be used inside the classroom. Theories such as the four model method that breaks down the types of encoding of texts. On one hand I feel these definitions are excellent. They give a practical name to a seemingly undefinable concept. On the other hand, in my own personal opinion, the definitions are too vague. It seems like I try to get close enough to the answers I am searching for the slip through my fingers. I understand most of these concepts, I read about them in a practical application, and yet I cannot make the leap from paper to my classroom.
I understand what critical literacy is, but I have yet to find a way to put it into words or properly apply it to the classroom. Hopefully I will soon.