Not saying that at all. As a historian, I take information from other theories and speculations and their sources, then re-interpret it. For instance, I am working on a paper right now examining the motivation of France in entering the Revolutionary War. I've got dozen of both secondary sources (what other people have said) and some primary sources (What people at the time said) I use both to prove the topic of my paper.

New ways of interpreting old data are coming about all the time. Borderlands history is a good one to look at and is relatively new. Queer history is another. Nothing about the data is new for the most part- it's all things examined before. Now it is being examined in a new light.