Part 1: Preface This is the preface to a timeline in which the Jewish philosopher Baruch Spinoza, after being excommunicated in Amsterdam, founds an Enlightenment-based Jewish sect in Constantinople. In OTL, Spinoza (1632-1677) was one of the first philosophers to marry Jewish thought with the emerging ideas of the Enlightenment, presaging the works of the Haskalah movement more than a century later. Not since Maimonides, and possibly not since Philo Judaeus in first-century Alexandria, had any Jewish philosopher been so receptive to contemporary Western thought. Spinoza has been called the first Jewish pantheist, and his deism and rationalism - not to mention his rejection of theological hierarchy and championship of intellectual freedom - were revolutionary for the time. In 1656, these ideas landed him in trouble before the rabbinic authorities of Amsterdam, who declared him _herem_, a decree equivalent to excommunication. Subsequently, he made a living as a lens grinder and primary teacher while writing philosophical treatises. Only one of these - a criticism of Descartes - was published in his own name during his lifetime, although some of his other works were published anonymously and he corresponded with other contemporary philosophers. In 1677, at the age of 45, he died of a lung disease contracted as a result of breathing dust while grinding lenses.

The POD for this timeline is 1660. In that year, the Amsterdam synagogue petitioned the municipal government to declare Spinoza a "menace to all piety and morals." In OTL, he left Amsterdam for good shortly thereafter, but continued to reside in the Netherlands. In the ATL, the rabbinic authorities are more successful, and succeed in having Spinoza exiled from Holland. His destination is a place where Jews are emancipated and where a rich Jewish intellectual life exists: the Ottoman Empire. During the mid-17th century, the Jews of the Ottoman realm were concentrated in four cities: Salonika/Thessaloniki, Constantinople/ Istanbul, Smyrna/Izmir and Safed. Of the four, Salonika had the largest Jewish community, with some 80,000 Jews forming a majority of the city's population. Salonika, however, tended to be a theologically conservative city, possibly for the very reason that its Jewish community was largely self- sufficient. Its thirty synagogues were organized in a loose alliance governed by an elected board, and the rulings of this board were binding on all Jews of the city. Such a hierarchy would have little room for a maverick like Spinoza. Neither would Smyrna. Not only was Smyrna also a provincial and conservative city, but it had recently been home to another famous Jewish troublemaker, the false messiah Sabbatai Zevi. At the time of the POD, Zevi had been expelled from Smyrna for heresy less than a decade earlier. The last thing the religious authorities of Smyrna would want is another heretic in their midst, especially one whose reputation precedes him. Safed has its attractions. In 1660, the Jewish community of Safed was relatively new and was in a state of intellectual ferment; among other things, Safed was the site of the first Gutenberg-type printing press in Asia. The trouble, at least from Spinoza's point of view, is that the prevailing currents of thought in Safed were mystical, and stood in direct opposition to his rationalism. That leaves Constantinople, whose 20,000 Jews were the most worldly and influential in the Ottoman Empire. It is here, among the court physicians and civil servants of the Ottoman capital, that Spinoza finds fertile ground for his progressive philosophies. Although the rabbis of Constantinople complain, Spinoza develops a following among the wealthier and more assimilated Jewish families.

By 1664, Spinoza has published his Ethics and the Treatise on God, Man and His Well-Being, both of which are derived from ideas he conceived prior to the POD. Unlike OTL, he not only publishes these books in his own name but does so as a man of God rather than a secular philosopher. His congregation, by now numbering thousands, recognizes him as its spiritual leader, and Jews from other Turkish cities begin to come to his synagogue to study. The established rabbinic authorities excommunicate him once again, and his followers with him, but by then the movement has taken on a life of its own. The idea of liberal Judaism, in which Jewish scripture is married to contemporary philosophy and in which emancipated Jews take full part in the life of their country, has begun.