Candor - A Must?

I am reading a book written by Jack Welch titled "Winning" in which he excellently describes about candor and what it actually means in an organizational context (both as a leader and as a manager). I totally agree with the concept of candor but would like to know as to how far can this concept be stretched!?? Is it too good to be frank?? Is freedom from prejudice the best thing at all given occassions?? Is it OK to be impartial at all times?? Is it good to be open at all times and to all people?? Well, I believe, obviously the answers to the above is an "Unconditional NO" for the simple reason that everyone is a prisoner of his / her own experience and no one can eliminate prejudices....u have to just recognize em'! Feel free to share your thoughts...