Jews and non-Jews alike may not commit adultery. Yet the spiritual damage of such an illicit union between Jews harms the souls and lives of their progeny for all generations. Such is the combined effect of two verses in the Torah, “You will be a kingdom of priests and a holy nation unto Me,” and “A mamzer may not enter into God’s marriage group even after the tenth generation.”
Who is a mamzer? According to the halacha, a mamzer is the child of a Jewish woman whose marriage to the child’s Jewish father is biblically prohibited and ineffective and subjects the couple to the punishment of death if the violators were warned in advance and witnesses were present or karet, premature death at the hand of God, in the event they were not warned or no witnesses were present. The Torah lists twenty-one mamzer-producing marriages, including the union of a married woman with a married man who is not her husband.
There are other marriages that are forbidden by the Torah, known as chayavei la’avim, that are not mamzer-producing marriages. That is because such marriages when entered into, in violation of the prohibition, are nevertheless effective and subject the violators to the punishment of lashes rather than karet. For example, the marriage of a kohen, a priest, to a divorcee or to a convert to Judaism, though prohibited, is effective and subjects the violators to the punishment of lashes. The child of such a marriage is not a mamzer but rather a chalal, who is merely disqualified from certain priestly rights and duties.
The child of a Jewish mother from a union with a non-Jewish father is not a mamzer. Such a child is Jewish and untainted and according to most opinions cited in halacha, requires no conversion. The child of a non-Jewish mother from a union with a Jewish father is also not a mamzer. Such a child is a non-Jew and is not considered the child of his father under Jewish law. Accordingly, such a non-Jewish child would not inherit from his Jewish father under Jewish law.
A non-Jew cannot be a mamzer because he is not a member of the Jewish people. A non-Jew born of an incestuous union who converts to Judaism is not a mamzer. This is because all converts to Judaism are considered the children of Abraham.
What are the consequences of being a mamzer? The main consequence is that a mamzer may not marry a Jew unless such Jew is either a mamzeret herself or a convert to Judaism. If a mamzer violates this prohibition and marries a Jew who is neither a mamzeret nor a convert to Judaism, the marriage is effective but the couple must undergo a Jewish divorce. Another consequence of being a mamzer is that the children of a mamzer are also mamzerim. The same is true of their children’s children ad infinitum. The only relief is in a dictum of Rabbi Yossi that the scourge of the mamzer will be erased when the Messiah arrives. According to most opinions, the importance of having children outweighs the concern of increasing the population of mamzerim. Accordingly a mamzer should marry a mamzeret or convert rather than remain unmarried even though this will result in increasing the number of mamzerim.
The child of a Jewish married woman born as a result of artificial insemination from a Jewish married man who is not her husband is not a mamzer. This is because there is no mamzer where there is no sexual union. But there is another concern involved in this situation. The child of the woman who underwent the procedure may unwittingly marry his own sister because he does not know who his father is. In order to avoid such concern, Rabbi Moshe Feinstein ruled that the donor of the semen should be a non-Jew because a non-Jew cannot halachically be considered the father of a Jewish child.
What are the rights of a mamzer? He or she is considered the child of his parents for all purposes including inheritance. Accordingly, the mamzer is entitled to a double portion in his father’s estate if he is the firstborn. The mamzer enjoys social rights like any other Jew. “Do not hate your brother in your heart,” “do not cheat your brother in business,” “you may not dominate your brother to break his spirit” – all these social laws apply to the mamzer. The mamzer qualifies to sit as a judge in a court of law adjudicating monetary matters. A person who dies and leaves a mamzer as his only surviving issue is not considered childless for the purposes of yibum. A mamzer must be circumcised like any other Jew but his mamzer status should be announced at the circumcision ceremony.
Questions of mamzer status often arise when a civilly divorced woman remarries before receiving aget, a Jewish religious divorce. The couple first marries civilly and lives together as husband and wife with the hope of regularizing their position later on by marrying in a synagogue after a get has been obtained.
“Little do they know,” said my father, Dayan Grunfeld of the London Beth Din, “that by their action, which amounts to adultery in Jewish law, they are forever prohibited to marry in a synagogue. Even more tragic, because entirely without personal guilt, is the fate of the unfortunate children of such marriages who, in Jewish law, must be considered as the issue of an incestuous marriage. It often occurs that the facts are discovered but a few days before the date of such illegitimate marriages, when everything has been arranged, friends and relatives invited who have often come from abroad to take part in the family festivity, and instead become witnesses of a great tragedy.
“All the other great problems of Jewish religious life, like Sabbath observance, kashrut, and education cannot be compared in gravity to this terrible problem. A Jew who does not observe Sabbath this week or does not eat kosher food this day will perhaps find a way to do it in the future. But in the sphere of illegitimacy of issue there is an awful finality which rends the Jewish people apart, prevents marriages between one Jewish section and another, and thus creates a problem of “inter-marriage” much graver than that marriage out of the faith which is usually designated by the term intermarriage.
“Rabbis could do a great deal in speaking to and influencing husbands who are civilly divorced, with a view to make them co-operate in the religious divorce, instead of using these sacred laws as a means of blackmail and holding their life partners up to ransom by demanding money from unfortunate Jewish women which they can neither afford to pay nor are under any obligation to pay. It is often such callous and irresponsible Jewish husbands who are to blame when Jewish women are driven to marry without a get in a civil registry office.”