Although Shakey has it down to a tee with this phrase I think it requires a little exploring.RaNDM G said:"There is nothing either good or bad, but thinking makes it so." -- William Shakespeare
It's interesting that in all cultures and even in different species certain things are considered bad.
If you threaten the young of a bear or a swan you better believe that the parents are going to come at you claws and beaks, so we could conclude that the threatening of young is considered a universal 'bad' thing. Also, murder of another member of the same species also seems to hold univeral status as a 'bad' thing but besides those I think bad really is subjective, the 'thinking makes it so' part of the Shakespeare quotation.
I think it's easier to define when something is good than bad becuase bad is so ambiguious. Is something that is missguided also bad or because it is missguided does that stop it being bad? Tricky stuff.
(Excellent thread by the way!)