Mark’s thesis is that the “weak", whom he prefers to label "impaired" (more on this later), throughout 1 Cor 8—11 are not what the traditional and prevailing interpretation asserts, namely Christ believers who are prone to idolatry because of their cultural baggage. Through 33 pages of argumentation Mark contends that the group in view is instead non-believing idolatrous Corinthians. And since no moniker is better, he labels them “polytheists”, by which he means “non-Christ-believing-non-Jews” (1).
Mark begins with a largely even-handed review of traditional interpretations of the referent of Paul’s term “weak”, which differ slightly in detail, but agree on the Christ-believing identity of the group. He lists several reasons why he thinks the traditional interpretation has had such convincing force. Among the reasons are (1) Paul’s reference to this group as “brothers/sisters”, (2) Paul’s assertion that to sin against them is to sin against Christ, and (3) Paul’s assumption that the weak brothers and sisters are vulnerable to influence by the knowledgeable. What’s more, Mark suggests prevailing meta-assumptions about Paul also function to support the traditional reading not least the prevailing view of Paul as one who no longer is a Torah-observant Jew since converting to Christ faith.