No photograph actually gives you the full, objective truth. Yes, the method to produce them is a direct, scientific method to reproduce sight. However, once you've factored in the viewpoint (metaphorically and literally) of the person behind the camera and the reasons they've framed the photo that specific way, cropped it that way, displayed it and described it that way, subjectivity reigns. The traditional view of the photograph as a mimic that faithfully transcribes reality without any filter is naive at best. Even scientific photographs are trying to communicate an idea (e.g. "This is what that looks like," or "This is how that is done."). And though the audience is free to interpret any photo in any way, context will ultimately sway most one way or the other. Context (and the control of it) is everything.
Congratulations, I just saved you 450 pages of plodding academic essays. The ideas are fascinating and any beginning student of photography would do well to understand them as thoroughly as they can, but most of this - to me - felt like page after page of repeating the obvious. The only truly interesting essays come in the last three chapters. The majority beforehand were an exercise in patience and willpower.