While discussing the inclusion of a Samaritan in a zimmun – a group of three joining together when reciting Grace after Meals – the Gemara quotes a baraita that teaches that an am ha’aretz may not be included in a zimmun.
The term am ha’aretz – literally, people of the land – already appears in the books of Ezra and Nehemiah as a term reserved for gentiles, not Jews. At a later stage, am ha’aretz became a derogatory epithet for a Jew who acts like a gentile. Fundamentally, an am ha’aretz is not just one ignorant of Torah, who might be called an ignoramus or fool [boor], but one who actually behaves in a non-Jewish manner. It is clear from the continuation of the baraita that am ha’aretz is not a clearly defined concept. There are many opinions with regard to characterizing an am ha’aretz. They range from the opinion that the term refers to one who does not serve Torah scholars and learn from them to the opinion that the term refers to one with no Torah, no Mishna and no manners. According to the first opinion, many learned people are included in this category. According to the second opinion, an am ha’aretz is the basest of individuals to whom the most derogatory epithets are generally applied. The common application of the term is to one devoid of spirituality, with no profession or occupation, no education, and no connection to Torah and mitzvot.
In the talmudic era, and even more so in later times, the situation changed in two respects. First, while there remained many who were uneducated, the am ha’aretz in its most extreme form disappeared, as even simple Jews upheld Torah and mitzvot to the best of their ability. Secondly, to avoid causing rifts among the nation in exile and in their wanderings, the halakhot restricting inclusion of most types of am ha’aretz were repealed.
Nowadays, even a full-fledged am ha’aretz may be included in a zimmun so as not to cause divisiveness within the Jewish people (Tosafot). Only one who has excluded himself from the community of Israel may not be included in a zimmun (Magen Avraham; Shulḥan Aruk, Oraḥ Ḥayyim 199:3).