The thesis paragraph
A thesis paragraph should state the overall issue and break it down into its main components (usually by stating a legal rule), providing the reader with a road map of the rest of the Discussion section.
On a smaller scale, the first paragraph of your analysis of a complex issue can do the same thing: identify the issue and break it down into its components, each of which will be addressed in turn. (Think of this as a "mini" thesis paragraph, if that helps.)
These brief articles describe what goes into an effective thesis paragraph:
Susan Duncan,
Thesis Paragraphshttp://ssrn.com/abstract=990435K.K. DuVivier,
Road Mapshttp://law.du.edu/images/uploads/Lawyering_Process_/Duvivier_articles/jan%201993.pdf(Both Chapter 6 in the textbook and, to a lesser extent, the above articles suggest that you ought to do more in a thesis paragraph than just identify the issue and state a rule that maps it out -- they say you should also describe how the rule applies to the issue and then offer a conclusion. I don't think those last two parts are essential; use your judgment in deciding how much to include.)