When I was doing my research at the British Library last year, I asked to look at a few British Fascist journals, and was surprised to be told that I could, as long as I moved over close to the librarians' desk so they could keep an eye on me. I was surprised, but after I looked at the newspapers I understood. It could have been very tempting to many people to rip those papers up, they were filled with such foul thoughts. In the interests of preserving history I had no such temptation, but I could understand the urge.
It's not pleasant, but it is yet another way in which history has been brought alive for me, and in which my own motivations for doing history have been made clear. It really matters that someone reads these books, and reminds others about what we can become if we are not careful.
As an afterthought: This is just another reason why I'm concerned that the British Government has recently decided to cut 40% of its funding of its universities, specifically targeting the arts and humanities. [See Naomi Wolf's take on the matter here.] Because, apparently, science and technology are the only things that matter. Lip service will be paid to the crucial part the arts and the humanities play in our civilisation. Politicians will pretend that an insightful and honest interpretation of the past matters to them, and that history is not merely a tool for their own personal axe-grinding. And, meanwhile, people will not understand what happened, because there will be no money to read old things at the British Library.