Ok, so you are selective in what you choose to accept as fact. That's fine, we won't get into bias effects and the subjectivity of any possible definition of tangibility.
It's also interesting that you would categorise the holocaust as a meme or an idea, but I think that pretty much sums up the way your own personal biases affect your thinking process.
It's also interesting that you would categorise the holocaust as a meme or an idea, but I think that pretty much sums up the way your own personal biases affect your thinking process.