How can you define human nature? Is it fundamental to our identity or something else? Can what is hidden truly be hidden? Will a book titled 'A Journal of Impossible Things' provide the answers, or will a simple watch tell far more than time? This is our review of 'Human Nature', Doctor Who Series 3 Episode 8.  All this - and more - in episode 144 of Discussing Who.  Hosted by Kyle Jones, Lee Shackleford, and Clarence Brown.