"When it comes to understanding how reality works,
* It doesn't matter what what believe
* It doesn't matter what we want to be true
* It doesn't matter what we refuse to believe
* It doesn't matter what we fear is true"
I disagree on two counts.
First, there are barriers created by aesthetics. Einstein's resistance to simple QM is only the most famous. A recent Scientific American cover story tells how a minor adjustment to the completeness of evaluations of all the path integrals created by virtual particles made possible a simplification that put many evaluations within computational reach, and may thereby have made possible the integration of relativity with QM. We had a "preference" for completeness that turned out to be unnecessary and obstructionary, but until someone got over it, it held back science.
Second, there should be barriers created by justifiable fears. We should not investigate topics that might let your proverbial mad scientist work for Osama Bin Laden's successors and destroy us all. It is as crazy as buying a gun, loading it, putting in the hands of a three year old and pointing it at our own head.