I just finished reading an article in The New Republic which argues that history and the humanities are knowledge too. At times it felt like the author was yelling at his brother begging to be noticed. Personally, I feel that in general the author is correct, that history and humanities do plan an important role and can be considered as knowledge. However, the author makes one glaring mistake, he is equating the unified theories of everything in physics with everything, where it typically means a combination of all physical laws within physics both particle and cosmic, which would then move into chemistry and likely into biology. However, this type of theory of everything would stop there. It couldn't really combine natural selection as functions of chemicals in a specific manager do not necessarily mean a truer understanding of evolution. It would be able to explain how phenotypes are changed with genotypes, but not why one genotype/phenotype pair was selected over another without an understanding of the specifics of the environments at a time. A true theory of everything at that level would essentially be a simulation of the universe. It would be impossible to model in a series of equations beyond the fundamental laws of physics.
For the evolution of biological systems you have to understand the natural history of the world that the organisms develop and evolve. This is why when you read Sagan, Dawkins or any other biologists or cosmologist they argue that if you rewound the tape of history you'd get a different present day. Some things may have happened just slightly different enough and you'd have no humans. The understanding of the history of our world allows us to understand where the future of it is going.
In the same way, history does matter. There are branches of economics, such as evolutionary economics that use complexity models and work to ensure that the history of events are included in their models. What the major difference between typical theories of history and psychology and newer models of economics and complex systems of physics, is that we're able to test them using simulations. It is likely that in the future we'll be able to do the same thing with history. This will give us a deeper understanding of why our societies have developed as they have. One heavily contested aspect of evolution, which is mentioned in the article, is cultural inheritance, which is where the theory of memes came from. This approach doesn't suggest one type of people is better than another or one lifestyle is better than another, it simply says that in the environment that the culture resides it's more capable of surviving than others. This can go down deeper to smaller niches within the culture and how well they adapt to their environment.
Other aspects the author argues discusses is the differences in the acceptability (or perhaps the perception) of radical paradigm shifts in science compared to the humanities and history. He mentioned specifically Freud in psychology and Galileo in physics. He argues that Galileo was able to make changes in physics because he tackled an "easy" problem that had minimal level of complexity. He went after the theory of gravity and how objects fall at the same rate while Freud went after the entirety of the human psyche. I agree there is a difference of complexity, however the key differences between Galileo and Freud is that he was better able to explain the state of the world and when new scientific theories were produced they continued to explain what Galileo found but with more accuracy and expanded on them. When Freud was discredited it was more like discrediting Alchemy than going from Newtonian physics to Relativistic physics.
The key difference between many theories in humanities and in the rest of science is the lack of continuum between two major theories. Yes, Relativistic physics completely obliterated the value of Newtonian physics and created a new world (universe) view, but it solved the same problems or proved that many of the old problems were only problems because the theory wasn't complete enough.
The key that needs to be remembered in either science or humanities is that all models are wrong, but some are useful. Freud was wrong in how he looked at the human psyche, but his models allowed other theories to be tested and used and likely spawned Neuroscience and the bridging between neuroscience and many of psychological problems.