ABSTRACT
The category of time belongs to what philosophers have termed the categories of understanding, notions that frame all thought and that serve as the armature of intelligence, without which the mind would not be able to conceive of other things. The very first ritual discussed in rabbinic sources is the daily recitation of several biblical passages known as the Shema prayer. The daily recitation of the Shema structured time in particular ways. After discussing the Shema's proper timing, the Mishnah's focus shifts to other elements of the prayer's composition and the practice of its recitation, including a clause that exempts certain people from the very obligation of reciting the Shema. The mishnaic tractate Berakhot begins with delineating the times of the recitation of the Shema. Likewise, the mishnaic tractate on menstrual purity, Niddah, begins with a set of guidelines for determining the times of a woman's menstrual impurity.
