The main objective of this paper is to examine the nature of the grounds on which teachers rely to justify their activities and decisions in the classroom in order to gain an insight into the epistemology of teaching practice. Historically the foundational system of justification has dominated epistemological studies in philosophy. According to Goor, Heyting, and Vreeke (2004), the foundationalist model of justification arranges assertions in a hierarchical structure whereby a group of grounds or foundations are considered to be self-justificatory because of their special epistemological superiority. The application of the foundational system of justification in theoretical or what I call paradigmatic knowledge is widely acknowledged. By contrast, in practical domains like teaching, teachers’ activities may not be justified based on foundational or universal grounds. However, it is argued that teachers’ practices and their supporting beliefs and knowledge still need to be justified: teachers should reasonably show that they are not in “error” (e.g., Fenstermacher, 1994; Feiman-Nemser & Floden,1986 ).To act and reflect on teaching activities with “good” reasons and justifications help teachers step in a normative (i.e., what ought to do) direction, and thus develop their practice. Epistemological studies in the teaching practice do not, however, follow the same criteria and procedures as those of propositional knowledge. In other words, the concept of “true justified belief” may not be applied to the teaching practice. Boyles (2006) has argued that epistemological studies in education with regard to classroom practice are rare because epistemology has come to be seen from a traditional point of view that focuses on “true knowledge.” Drawing on Dewey, Boyles has pointed out that traditional definition of epistemology should be replaced by the new version of epistemology namely “warranted assertibility”. According to this perspective, “warranted assertions merge truth
