If you can't resolve them yourselves, go to the professor for help. Some people use this as an excuse for not talking in class. If you do this, admit it to yourself, and work on trying to find something to say. Usually, if you are prepared, you won't have a problem with finding issues to discuss or opinions to express. Put together some comments in your notebook before class based on readings or perhaps the last discussion.
Discussion takes practice, just like everything else.
If you are truly prepared, and still have a problem, chat with the professor. Final Words One of the single most important reasons for a seminar is to help people see connections between ideas. That's what really makes them exciting. But this all takes preparation, concentration, and practice. Seminar skills are not something with which you are born.