 350 years after the invention of the matter duplicator, the technology has been improved to the point where human beings can be duplicated, and it is common medical practice for surgeons to test their surgical procedures on duplicates of their patients before operating on the originals.As a result, the greatest insult that can be offered to a person is to claim that they are a duplicate rather than the original (the slang expression is "dupe").This is the reason identical twins such as Calvin and Benjamin Blair tend to hate each other's guts, as Cal and Benj do.