There is nothing intrinsic about Kaddish that makes it appropriate only for mourners. Chazanim regularly say the Kaddeishim during the tefilla. The main issue is regarding the Kaddish following Aleinu at the end of the tefilla (and in a few other places, during Shacharit). This was instituted to give mourners who are not able to be the chazan the opportunity to recite at least that Kaddish and to thereby elevate the souls of their departed parents. Thus, poskim write that if one whose parents are alive says Kaddish, it may give the impression that a parent has died, and we refrain from this in order that we “not open our mouth to the Satan.”[1]
In contrast, Kaddish D’Rabbanan was instituted because of the special impact that it has for the world in general. The gemara[2] mentions the saying of “Y’hei Shmei Rabba” (the focal point of Kaddish) after learning aggada (homiletic portions of the Torah) as one of two things that can keep the world in existence. In theory, and according to the great majority of classical sources,[3] this Kaddish need not be limited to those whose parents have passed away. On the other hand, there is an opinion that only one who does not have parents says Kaddish D’Rabbanan.[4] Even though this opinion is rejected, it is hard to deny that the perception of most people is that it is said only by mourners or those without parents.
This perception causes a situation where a parent may be understandably disturbed that his or her child is reciting Kaddish D’Rabbanan. Some authorities[5] contend that, under these circumstances, there is an element of “opening the mouth to the Satan.” What happens if a parent objects to the saying of Kaddish when it need not be objectionable? There is a major machloket among Rishonim in a case where a father tells his son not to recite Mourner’s Kaddish for his mother (the father’s wife, not a divorcee). The Maharam[6] says that the father’s objection, which has a logical basis, should be heeded, even though it is unfortunate, as it is important to say Kaddish for the mother. However, the Rama[7] says that we reject the father’s objection and instruct the son to say Kaddish for his mother.
The case in question is different from the Rama’s in ways that could suggest contrary rulings. On one hand, if the parents and others were more knowledgeable about the background of Kaddish D’Rabbanan, there would be no reason to object. On the other hand, there is less of a requirement to say Kaddish D’Rabbanan, especially after a learning session that is not part of davening. It is very common for group learning to end without Kaddish D’Rabbanan (for better or for worse, and that is not our topic now) even if mourners are present. So why create a questionable situation when one can finish the learning without a Kaddish?
We suggest the following approach, which is in line with that of Rav O. Yosef.[8] A parent has the prerogative to object to his son saying Kaddish D’Rabbanan, but the son need not ask permission from his parent in advance. If one wants to ask his parents, he can mention that a son with living parents is permitted to say that Kaddish and hope they do not object. If someone without living parents is present, he should ideally be the one to say Kaddish D’Rabbanan, but if no one is saying the Kaddish D’Rabbanan at the beginning or end of davening, then it is fine for anyone to recite it. (Rav Sh.Z. Orbach gave such instructions to a colleague of ours with living parents.) In any case, your friends at the minyan have no reason to complain.