The paper compares John Dewey's pragmatism and cultural-historical activity theory as epistemologies and theories of transformative material activity. For both of the theories, the concept of activity, the prototype of which is work, constitutes a basis for understanding the nature of knowledge and reality. This concept also implies for both theories a methodological approach of studying human behavior in which social experimentation and intervention play a central role. They also suggest that reflection and thought, mediated by language and semiotic artifacts, (...) serve the reorientation of activity and is vital in the development of new, alternative ways of action. That is why Dewyan pragmatism and activity theory supply means of understanding organizational behavior and change in human activities better than the concepts of practice based on rule following, routines or embodied skills. (shrink)