A neighbor was kind enough to give me a book I've been meaning to get for a while: R. Yitzhak Sheilat's (RYS) edition of the shiurim of R. Gedalya Nadel (RGN) zt"l. It's good stuff. I still have to finish going through it and to think about it more carefully. Still a few comments are in order.

The book covers the sources of halakhah, touching on well-known problems concerning the terms halakhah le-moshe mi-sinai (HLMM) and divrei soferim (as used by Rambam). Another chapter deals with the concept of rov (majority) and its relationship with probability. The longest chapter deals with the question of truth and myth in sefer bereishis. In other words, the good stuff.

Each of these merits a lengthy discussion, but for now I just want to make a few quick observations. Before I do, I should point out that RYS is a cautious fellow and has not made the book commercially available (although, it can be found in some stores). He also declares that anybody who finds certain views expressed in the book too racy should simply reject them. In that spirit, I will try to be discreet and understated and not try to fan flames.

With regard to HLMM, the problem is that the status of HLMM is assigned to a number of laws that are clearly late and clearly derabanan. Moreover, as Rambam argues, a law that originates at Sinai permits no dispute. Yet many laws assigned status of HLMM are clearly subjects of dispute (as pointed out by Havos Yair at great length). RGN's solution is similar to that of the the Netziv in his introduction to haamek sheilah and to that of R. YB Soloveitchik in the essay Shnei Sugei Masores in Shiurim LeZekher Abba Mari. In other words, as far as his neighbors in Bnei Brak are concerned, RGN is in some very very bad company. Read it yourself.

The term divrei soferim generally means derabanan and the Rambam explicitly identifies the two terms in a letter to Rav Pinchas haDayan. Nevertheless, the Rambam applies the term to laws learned from derashos that are generally regarded as deoraisa. Moreover, the Rambam himself treats laws that he calls divrei soferim as deoraisa; for example, kidushei kesef -- which Rambam says is divrei soferim -- are sufficient to establish a status of eishes ish deoraisa. RGN takes the path of R. Yitzhak Isaac Halevi that the term divrei soferim refers to the origins of the law and not its status, which (in the usual yeshivish sense of the terms) might be derabanan or deoraisa. RGN doesn't expand on the importance of the establishing the origins of the law as divrei soferim, but there are in fact many important consequences. (Both R. NE Rabinovich and RYS himself have written on this point.)

On the topic of rov, RGN argues cogently that bitul and other related ideas are concerned with assigning a single status to a mixed set. But he argues that the principle of kol kavua ke-mechtzah al mechtza is an exception in which an individual object is treated separately from the set from which it originated. I'm quite sure that RGN is wrong on that point (be-mechilas kevodo, but he was the sort who appreciated independent thinking). But explaining why will take us a bit far afield, so I'll save it for another day.

And sefer bereishis is an altogether different story.