A lot of thinkers seem to fall into the bias described by the aphorism, “when all you have is a hammer, everything looks like a nail.”
Consider Freud. Freud noticed, correctly, that a lot of psychological problems revolve around sexuality; and he erred by trying to say that all, or nearly all, psychological problems have to do with sexuality.
Adler did something similar. He correctly noticed that a lot of psychological problems revolve around self-esteem, and he erred by trying to say that all psychological problems revolve around self-esteem.
Now consider Wittgenstein. Wittgenstein correctly noticed that a lot of philosophical problems are due to confusions over language, and can be dissolved by pointing out and correcting the confusion implicit in the posing of the problem. He erred by saying that every philosophical problem can be resolved in this fashion. (In the Blue Book, for instance, he gives a quite unsatisfactory attempt to resolve the mind-body problem by saying that it is a confusion over language.)
Further, I think that the Western intellectual culture as a whole has fallen into the hammer-and-nails bias with respect to science. We correctly noticed that a lot of questions can be answered through the scientific method; and we erroneously decided that the scientific method should be how we answer all questions. We failed to notice its inadequacy in the areas where it is inadequate, such as psychology.
I also fell into this bias for a while with the Ra material, trying to solve every problem using the tools it provides. I have seen some of my friends do the same thing with the Ra material.
So it seems to be quite common for us to find really shiny hammers and then distort our perceptions into a world of nails. But the world is complicated enough that we need more than one tool in our toolkits.
Another thing we can notice about this bias is that it seems to occur more frequently when one is the inventor of the hammer. Freud, Adler, and Wittgenstein were all the inventors of their hammers, and all of them tried to turn everything into a nail. So it seems like one is especially vulnerable to this bias with ideas of one’s own invention.