A visitor, named "visitor" appropriately enough, wondered, in a comment, about the title of this blog.  He/she guessed that it was from Chuang Tzu – and that is correct.  When I first started out, on my very first blog day, July 1, 2005, I did a post on "Why ‘Useless Tree’".  You can click through for one version of the Chuang Tzu story (there are several).  As to the references in that early post to Aidan, check out the right column for various posts – this one might be the best place to start.