How many children should a Jewish couple have? Although that may seem like a strange question and one that impinges on the private and most intimate life of a couple, it has been addressed by Jewish law in the past and is now the subject of a new teshuva (responsum) issued recently by the Committee on Jewish Law and Standards of the International Rabbinical Assembly of which I am pleased to be a member. Jewish law (Halacha) has dealt with this because the very first mitzva found in the Torah is: "And God blessed them; and God said to them, 'Be fruitful and multiply and fill the earth and replenish it...'" (Genesis 1:28). It should be noted that this is not phrased in the Torah as a command in a negative sense and certainly not as a punishment, but as a blessing. To understand how to fulfill this mitzva the sages discussed and debated it. Who is responsible to fulfill it? How many children and of what sex are required? Without going into details, suffice it to say that the traditional answer has been that the mitzva is fulfilled when a couple has had two children, one boy and one girl. The Talmud, however, determined that two children are the minimum, but that Jews should continue to have as many children as they can (B. Yevamot 62b), and Maimonides codified this as law. The Rabbinical Assembly teshuva does not change that, but is concerned with the current situation in Jewish life in which, with the exception of the haredim and, to some extent other observant Jews, most Jewish families in Diaspora communities barely fulfill that minimum of two, so that the Jewish population is not even reproducing itself. There are many factors that contribute to this, including the fact that more and more Jewish women are professional career women who do not marry until later. Like other such women they are inclined to have one child or maybe two. It may be true that the world is becoming overpopulated, although some countries in Europe are encountering the opposite problem of aging populations with insufficient young people, and that is what is happening in Jewish communities as well. Everywhere except in Israel, the Jewish population is diminishing, with the result that we are not even reproducing ourselves. Committed Jews should be concerned about the depletion of the Jewish population, especially in light of the fact that a third of the world Jewish population was exterminated in the Holocaust. Rather than making up for that loss we seem to be adding to it, especially when we take into account those Jews lost to us through assimilation and intermarriage. The proposal of the Rabbinical Assembly teshuva, therefore, is that Jewish couples who can have children and do not suffer from specific physical, mental or other problems preventing it should add one more child or even more to the two required by Halacha, a "mitzva child," to replenish the Jewish world and assure future Jewish existence. To quote the teshuva, "The world's Jewish community has not recovered numerically from the devastating losses during the Nazi era. Demographic studies point to a Jewish birthrate that will not maintain the Jewish population in the United States, with serious implications for the future of the American Jewish community, the Jewish people as a whole, and Judaism itself. It is essential that we encourage fertile Jewish couples to have at least two children in compliance with the early Halacha, and one or more additional children, who are mitzva children in the additional sense that they help the Jewish people replace those lost in the Holocaust and maintain our numbers now. Adopting children, converting them to Judaism, if necessary, and raising them as Jews helps in this effort as well. "Why the term 'mitzva children'? Both because having more than two children is mandated by later Jewish law and also because in our day the term mitzva is used by Jews to describe 'good deeds.' In a sense, Jews are saying that they feel commanded by God to do the right thing, that which they feel God would want them to do in the situation. Every couple who has at least a third child should feel that that child is a mitzva child in this sense, for the parents are not only replacing themselves as minimally commanded, but making an additional contribution to assuring that the Jewish people will survive to help to fulfill God's plan for the world." This teshuva, written jointly by Rabbis Kassel Abelson and Elliot Dorff, was passed overwhelmingly by the Committee on Jewish Law and Standards and will become part of the regular counseling of Masorti/Conservative rabbis throughout the world when meeting couples about to be married. It is time that this problem was addressed and that Jews took seriously the threat to our existence that low birthrates present. In doing so, they perform a double mitzva and receive the blessing with which God blessed our first ancestors. The writer is an author and lecturer who serves as the head of the Rabbinical Court of the Masorti Movement.