I can't show you the textual description of a class in Smalltalk, because there isn't one. Instead of writing a text file to define a program, in Smalltalk use describe a class using a visual interface. This was a revolutionary idea in 1980, when Smalltalk was released, but now that Visual Basic and Delphi and other systems use similar ideas the concept is not quite so revolutionary.
Using the Smalltalk browser, the user selects the parent class for the new class being defined. A message is then given to the parent class, which constructs the new child class.