Literacy may be defined as a set of changing practices and techniques with the social technology of writing. The distribution of literate practices by institutions has been tied up with knowledge and power in societies. Who gets what kinds and levels of literacy from schooling is directly related to the "division of literate labor." This is reflected in stories of reading practices in a 13th century monastery in Toronto (Ontario, Canada) in English-as-a-Second-Language instruction for women immigrants from the Azores; and in literacy instruction among the Vai, a tri-literate Western African tribe. In all three examples, and in current schooling, three elements appear: (1) a corpus of texts; (2) selected genres for reading and writing; and (3) events and practices. A new four-part model permits a rethinking of how instruction shapes reading practices. The key elements of proficient, critical reading as social practice include coding, semantic, pragmatic, and critical competence. Coding competence means learning the role of code breaker. Adapting to the role of text participant is what is meant by semantic competence. Pragmatic competence involves learning to be a text user. The ability to analyze text implies critical competence. A socially critical literacy program would systematically introduce children to the four elements of reading practice at all stages of literacy instruction. In "postmodern" society, nothing short of a critical social literacy will suffice. (Twenty-nine references are attached.) (SG)