A very fine article on a very delicate subject, and as someone who generally prefers to ignore if I feel my opinion will offend, I try to always be truthful. But the truth is funny, subjective; your own truth can be conscious or buried in unconscious thought. Like quality, at times it is undefinable, something felt rather then truly tangible. Where as fact and fiction need defined lines, truth is, as you mentioned, muddied by perception. As a writer, people around me when questioned will generally offer praise, but I know when it isn't deserved. The best advice was from a friend who after looking at some of my books handed them back and said, 'These aren't very good, you can do better, try harder.' Anyone who trusts me enough to tell me something honest that may hurt me, wins a lot of respect in my book.