A few days ago I mentioned my trip to see the DSS in Philly which also included listening to a special lecture by Profs. John Collins and Lawrence Schiffman. I made a few notes about their respective viewpoints (see here). Prof. Shiffman saw my post and has kindly responded to it on his own site with additional information, some corrections to my (mis)understanding of his points (and that of Prof. Collins), and a few clarifications.
I cannot stress how impressive Prof. Schiffman was as a lecturer. He was very engaging, enthusiastic, warm, and exceptionally knowledgable. I am almost willing to say that I enjoyed the lecture more than the exhibit!!!