texts, they hold that we cannot confirm the origin or date of most statements and laws, and that we can say little for certain about their authorship. In this view, the questions above are impossible to answer. See, for example, the works of Louis Jacobs and Shaye J.D. Cohen. Some scholars hold that the Talmud has been extensively shaped by later editorial redaction, but that it contains sources we can identify and describe with some level of reliability. In this view, sources can be identified by tracing the history and analyzing the geographical regions of origin. See, for example, the works of Lee I. Levine and David Kraemer. Some scholars hold that many or most of the statements and events described in the Talmud usually occurred more or less as described, and that they can be used as serious sources of historical study. In this view, historians do their best to tease out later editorial additions (itself a very difficult task) and skeptically view accounts of miracles, leaving behind a reliable historical text. See, for example, the works of Saul Lieberman, David Weiss Halivni, and Avraham Goldberg. Modern academic study attempts to separate the different "strata" within the text, to try to interpret each level on its own, and to identify the correlations between parallel versions of the same tradition. In recent years, the works of R. David Weiss Halivni and Dr. Shamma Friedman have suggested a paradigm shift in the understanding of the Talmud (Encyclopaedia Judaica 2nd ed. entry "Talmud, Babylonian"). The traditional understanding was to view the Talmud as a unified homogeneous work. While other scholars had also treated the Talmud as a multi-layered work, Dr. Halivni's innovation (primarily in the second volume of his Mekorot u-Mesorot) was to differentiate between the Amoraic statements, which are generally brief Halachic decisions or inquiries, and the writings of the later "Stammaitic" (or Saboraic) authors, which are characterised by a much longer analysis that often consists of lengthy dialectic discussion. The Jerusalem Talmud is very similar to the Babylonian Talmud minus Stammaitic activity (Encyclopaedia Judaica (2nd ed.), entry "Jerusalem Talmud"). Shamma Y. Friedman's Talmud Aruch on the sixth chapter of Bava Metzia (1996) is the first example of a complete analysis of a Talmudic text using this method. S. Wald has followed with works on Pesachim ch. 3 (2000) and Shabbat ch. 7 (2006). Further commentaries in this sense are being