Oh gosh, where do I start with this.
This is going to sound very high falutin', but one of the main reasons I am a librarian, aside from the fact that I get a paycheck from it, is that I firmly believe that one of the foundations of democracy is the free and open access to information and knowledge. Without this freedom to know, which I think Roosevelt should have included in his famous speech,
http://www.libertynet.org/~edcivic/fdr.html, I cannot see the democratic and open society survivng. Providing this information is my contribution.
Please note that for me, fiction is included in "information."
This, of course, appears to beg the question, what if the information you are providing is inaccurate, inflammatory, ephemeral, evil, or just plain ridiculous. Should I hand to a young and impressionable patron The Protocols of the Elders of Zion?
http://www.holocaust-history.org/short-essays/protocols.shtml If someone I suspect to be a terrorist asks for a book on bomb making, do I provide it? Do I give Kevin Trudeau's book of arrant nonsense to an obviously ill person?
The answer is yes.
Bear in mind that I have additional options open to me. "If you are interested in this book, you might also want to look at...." "Would you like to see some reviews about this book?" "This book has an interesting history; would you like to look into this?" This is actually a library technique called "Readers' Advisory."
If the patron isn't interested, that isn't my business. My business is to supply the information they have requested. And if I started making it my business, I become an arbiter of information, not a librarian.