In any event, it would seem that Keriat Shema is a davar she’b’kedushah that needs the presence of 10 men. (One might also assume that the two kedushot of Yotzer Ohr and U’va Letziyon would also require a minyan.)
The resolution of this difficulty is as follows: The mishnah only refers to an individual fulfilling the obligations of others, i.e., by them answering Amen. (The Radvaz explains that he is fulfilling his own obligation while the others are assisting him in doing so even though they already have prayed. They are adhering to the principle of “kol yisrael areivim zeh bazeh – each Jew is responsible for his fellow Jew” to enable another Jew to discharge his obligation of tefillah b’tzibbur. In such an instance – for the purpose of keriat shema b’tzibbur – a minyan is required.
The Abudarham notes that the reason kedushah was instituted in Yotzer Ohr (and similarly in U’va Letziyon) was to refute those who deny Hashem’s presence and say that Hashem abandoned this earth and gave its rule over to the sun and other luminaries. By reciting kedushah, we relate that all creation, including the luminaries, sanctify Hashem. However, as Abudarham states, this is merely a sippur devarim, relating that which is said. These two kedushot are the recital of continuous praise by the malachei hasharet, the angels who serve Hashem. These angels are referred to and described in our tefillah.
The kedushah of chazarat hashatz, however, is different. Rabbi Yaakov Emden (in his siddur Beit Yaakov) explains that this kedushah is a fellowship, or joining, of the congregation with the malachei hasharet as all offer Divine praise.
(To be continued)
Rabbi Yaakov Klass, rav of Congregation K’hal Bnei Matisyahu in Flatbush, Brooklyn, is Torah Editor of The Jewish Press. He can be contacted at firstname.lastname@example.org.