www.TheLogician.net© Avi Sion All rights reserved


© Avi Sion, 1995, 1997 All rights reserved.

You can BUY online, Amazon.com (in paperback or kindle/.mobi form), at Lulu.com (in hardcover, paperback or e-book / .epub form ), and at many other online stores.


Judaic logic: A Formal Analysis of Biblical, Talmudic and Rabbinic Logic is an original inquiry into the forms of thought determining Jewish law and belief, from the objective perspective of a logician. The author’s previous treatise, Future Logic: Categorical and Conditional Deduction and Induction of the Natural, Temporal, Extensional and Logical Modalities, was a large-scale study of formal logic and epistemology; in the present work, his purpose is to consider the logic employed within his religion, Judaism, and honestly estimate the extent to which it fits into the general norms and whether it has any contributions to make to them. It covers a wide range of topics:

· A brief overview of the sources of Jewish law (the Halakhah), and a quick introduction to generic logic theory (induction and deduction), for the uninitiated.

· The new discovery of an explicit formulation of the principles of adduction in the Torah (the Pentateuch), written long before their acknowledgement in Western philosophy and their assimilation in a developed theory of knowledge (epistemology).

· An original and thorough formal analysis of a-fortiori logic (the qal vachomer type of argument, the most deductive of Judaism’s interpretative processes), together with a detailed investigation of its use in the Tanakh (the Jewish Bible) which reveals it to be much more widespread than traditionally supposed.

· A reflection on the psychological and social factors affecting both religious and secular thought, which may cause people to deviate from openness and objectivity, whether within one of these domains or in relation to the other.

· An examination of some of the main similarities and differences between the methods and databases of religious and secular pursuits of knowledge, which shows the overwhelmingly inductive (rather than, as traditionally assumed, deductive) methodology of Talmudic and Rabbinic thought.

· A presentation, in considerable detail, of traditional teachings of Judaic logic, including principles of interpretation (hermeneutics) and organization (heuristics); and suggestions for methodical study.

· A detailed and incisive formalization and evaluation of the 13 Midot of R. Ishmael and other fundamental principles of exegesis of Jewish law – a completely novel research effort (which may be considered as the central motive of the work), revealing impartially the strengths and weaknesses of Talmudic and Rabbinic modes of thought.

· A formal study of the ethical logic (deontology) found in Jewish law, to elicit its universal aspects and its peculiarities.

· Finally, an examination of possible bases and motives of belief in G-d, and, more broadly, in the religious tradition; and a critical assessment of some of the less formal legal generalities adopted by the Rabbinic tradition.

Judaic Logic is of both theoretical and practical value, to students of Bible and Talmud and to students of Logic and Philosophy alike. The work’s universality lies in its efforts both (a) to bring Judaic logic into the general fold, demystifying it and showing the extent to which its processes are, or are not, commonplace; and (b) to draw from it any lessons of value to logic theory and practise in general. In fulfilling the first of those tasks, this work incidentally provides Bible and Talmud students, and more specifically the deciders of Jewish law, with wider methodological perspectives and powerful new technical tools. In fulfilling the second, it provides the secular layperson, the scientist or philosopher, and in particular the logician, with novel historical insights and formal instruments.