By reason of their great number, their importance, and their compact union, the Jews in Poland formed a state within a state. The general synod, which assembled twice a year at Lublin and Jaroslaw, formed a legislative and judicial parliament from which there was no appeal. At first called the Synod of the Three Countries, it became in the first quarter of the seventeenth century the Synod of the Four Countries (Vaad Arba Arazoth). An elective president (Parnes di Arba Arazoth) was at the head, and conducted public affairs. The communities and rabbis had civil, and, to a certain extent, criminal, jurisdiction, at least against informers and traitors. Hence no Jew ventured to bring an accusation against one of his race before the authorities of the country, fearing to expose himself to disgrace and contempt from public opinion, which would have embittered his life, or even entailed death. Almost every community had its college of judges, a rabbi with two assessors, before whom every complaint was brought, but the final decision rested with the synod. The synod also concerned itself about honesty in dealing and conduct, and in weight and measure, wherever Jews were affected.
The study of the Talmud in Poland, established by Shachna, Solomon Lurya, and Moses Isserles, reached a pitch attained at no previous time, nor in any other country. The demand for copies of the Talmud was so great that in less than twenty years three editions had to be printed, no doubt in thousands of copies. The study of the Talmud was a greater necessity in Poland than in the rest of Europe. The rabbis, as has been already said, had jurisdiction of their own, and decided according to Talmudical and Rabbinical laws. The great number of Jews in Poland, and their fondness for litigation, gave occasion to intricate law cases. The rabbi-judges were obliged to go back to the source of law, the Talmud, to seek points of support for such cases. The contending parties being themselves well informed and acute, the reasoning of the rabbis had to be flawless to escape criticism. Hence Rabbinical civil law in Poland met with extraordinary cultivation and extension, to adapt it to all cases and make it available for the learned litigants. Thus the ever-growing subtlety of the method of Talmud study depended on current conditions and wants, and on the circumstance that each Talmudist wished to surpass all others in ingenuity.