I was reading Jacob Neusner's "Scriptures of the Oral Torah", and in the chapter on the Mishnah (whatever opinion one might hold of the author) there is an excellent overview of this key work of Judaism, and the philosophical message in it. The following, then, is an extract from Neusner's book.
The Division of Agriculture treats two topics, first, producing crops in accord with the scriptural rules on the subject, second, paying the required offerings and tithes to the priests, Levites, and poor. The principal point of the division is that the Land is holy, because God has a claim both on it and upon what it produces. God's claim must be honored by setting aside a portion of the produce for those for whom God has designated it. God's ownership must be acknolwedged by observing the rules God has laid down for use of the Land. In sum, the Division is divided along these lines: (1) Rules for producing crops in a state of holiness- tractates Kilayim, Shebiit, Orlah; (2) Rules for disposing of crops in accord with the rules of holiness- tractates Peah, Demai, Terumot, Maaserot, Maaser Sheni, Hallah, Bikkurim, Berakhot.
The Division of Appointed Times forms a system in which the advent of a holy day, like the Sabbath of creation, sanctifies the life of the Israelite village through imposing on the village rules on the model of those of the Temple. The purpose of the system, therefore, is to bring into alingment the moment of sanctification of the village and the life of the home with the moment of sanctification of the Temple on those same occasions of appointed times. The underlying and generative theory of the system is that the village is the mirror image of the Temple. If things are done in one way in the Temple, they will be done in the opposite way in the village. Together the village and the Temple on the occasion of the holy day therefore form a single continuum, a completed creation, thus awaiting sanctification.
The village is made like the Temple in that on appointed times one may not freely cross the lines distinguishing the village from the rest of the world, just as one may not freely cross the line distinguishing the Temple from the world. But the village is a mirror image of the Temple. The boundary lines prevent free entry into the Temple, so they restrict free egress from the village. On the holy day what one may do in the Temple is precisely what one may not do in the village. so the advent of the holy day affects the village by bringing it into sacred symmetry in such wise as to effect a system of opposites; each is holy, in a way precisely the opposite of the other. Because of the underlying conception of perfection attained through the union of opposites, the village is not represented as conforming to the model of the cult, but of constituting its antithesis. The world thus regains perfection when on the holy day heaven and earth are united, the whole completed and done: the heaven, the earth, and all their hosts. This moment of perfection renders the events of ordinary time, of "history," essentially irrelevant. For what really matters in time is that moment in which sacred time intervenes and effects the perfection formed of the union of heaven and earth, of Temple, in the model of the former, and Israel, its complement. It is not a return to a perfect time but a recovery of perfect being, a fulfillment of creation, which explains the essentially ahistorical character of the Mishnah's Division of Appointed Times. Sanctification constitutes an ontological category and is effected by the creator.
This explains why the Division in its rich detail is composed of two quite distinct sets of materials. First, it addresses what one does in the sacred space of the Temple on the occasion of sacred time, as distinct from what one does in that same sacred space on ordinary, undifferentiated days, which is a subject worked out in Holy Things. Second, the Division defines how for the occasion of the holy day one creates a corresponding space in one's own circumstance, and what one does, within that space, during sacred time. The issue of the Temple and cult on the special occasion of festivals is treated in tractates Pesahim, Sheqalim, Yoma, Sukkah, and Hagigah. Three further tractates, Rosh Hashshanah, Taanit, and Megillah, are necessary to complete the discussion. The matter of the rigid definition of the outlines in the village, of a sacred space, delineated by the limits within which one may move on the Sabbath and festival, and of the specification of those things which one may not do within that space in sacred time, is in Shabbat, Erubin, Besah, and Moed Qatan. While the twelve tractates of the Division appear to fall into two distinct groups, joined merely by a common theme, in fact they relate through a shared, generative metaphor. It is, as I said, the comparison, in the context of sacred time, of the spatial life of the Temple to the spatial life of the village, with activities and restrictions to be specified for each, upon the common occasion of the Sabbath or festival. The Mishnah's purpose therefore is to correlate the sanctity of the Temple, as defined by the holy day, with the restrictions of space and of action which make the life of the village different and holy, as defined by the holy day.