Even those far removed from Jewish learning know that it is the mother who determines the Jewish status of a baby. Why this is so is not clearly spelled out. The simplest and most obvious reason would seem to be the fact that while we always know who the mother is, the identity of the father is less certain. The Talmudic assertion that "the majority of relations a woman has is with her husband" (Sotah 27a) is just that--a claim about the majority. However, a minority are not.
"Whoever starts in a mitzvah, we tell him to finish"; "a mitzvah that comes to your hand, do not let it wait". These and other similar sentiments express the view of our Sages that one must take advantage of an opportunity for a mitzvah without delay and complete the task at hand. This is not only a moral exhortation to complete our duties, but can have legal consequences.
Innocent until proven guilty is a fundamental norm of Western jurisprudence. This concept goes back until at least Talmudic times, when our Sages assert that all Jews have a chezkat kashrut, a presumption of honesty. Yet as human beings, we are inherently biased--"man is close to himself" (Yevamot 25b)--and, try as we may, we can never be 100% objective. Generally, such biases can be, at least from a legal perspective, ignored. However, at times the overwhelming power of self-interest can colour--consciously or not--our perception of the truth.
By dint of the fifth amendment to the Constitution, US citizens are protected from being forced to give self-incriminating testimony; pleading the fifth is a common refrain in many a courtroom. Jewish law goes one step further; it forbids the giving of self-incriminating evidence. Ein adam masshem aztmo rasha, a person cannot turn himself into an evil person (Yevamot 25b). Thus, one who admits to having killed someone cannot be convicted based on his own testimony.
All great pieces of literature can be understood on multiple levels, over multiple time periods, and by a variety of cultures. There is no greater piece of literature than the Bible: "Turn it and turn it, as all is in it" (Avot 5:22). We read, reread, and then read it again as we seek to deepen our understanding of this wonderful text. We begin our study of Torah by seeking to understand its p'shat.
Life is not always fair. So much that befalls us--both positive and negative--is beyond our control. And there is little that is less fair than being born a mamzer, an illegitimate child. Through no fault of one's own, one is stigmatized for life, unable to marry most Jews. Such status is the result not of an unfortunate accident, but of a deliberate sin of the most heinous kind: adultery or incest by the mamzer's parents.
On Yom Kippur afternoon, the Torah reading focuses on the Jewish sexual ethic. The Torah has a relatively long list of relatives with whom intimacy would be considered incest. If one were to "marry" one of these people--say, one's aunt--such a union would be of no standing. There is a second group of prohibited marriages, issur kedusha, where one may not marry someone; but such a forbidden marriage, while a violation of the sanctity of marriage, would be recognized as valid.
It is the Jewish woman who is privileged with bestowing Jewishness to her offspring. Yet while the mother determines the Jewish status--or lack thereof--of her offspring, it is the father who determines particular family status. Thus, whether one is Kohen, Levi, or Yisrael is determined by the father.