Purpose -The purpose of this paper is to theorize the theory-practice gap and to provide examples of how it currently expresses itself and how it might be addressed to better integrate between the worlds of thought and praxis. Design/methodology/approach -Two empirical examples exemplify how the theory-practice gap is an institutionally embodied social reality. Cultural-historical activity theory is described as a means for theorizing the inevitable gap. An example from the airline industry shows how the gap may be dealt with in, and integrated into, practice. Findings -Cultural-historical activity theory suggests different forms of consciousness to exist in different activity systems because of the different object/motives in the world in which we think and the practical world in which we live. A brief case study of the efforts of one airline to integrate reflection on practice (i.e. theory) into their on-the-job training shows how the world in which pilots think about what they do is made part of the world in which pilots live. Practical implications -First, in some cases, such as teacher education, institutional arrangements can be made to situate education/training in the workplace. Second, even in the training systems with high fidelity, high validity (transferability) cannot be guaranteed. Originality/value -The approach proposed provides a theory not only for understanding the theory-practice gap but also the gap that exists even between very high-fidelity ("photo-realistic") training situations and the real-world praxis full of surprises.The question whether there is truth to human thinking is not a question of theory but a practical question. In practice man has to prove the truth, that is, the reality and power, the this-sidedness of his thinking. The debate over the truth or non-truth of thinking, which isolates itself from practice, is a purely scholastic question (Marx and Engels, 1958, p. 533).The current issue and full text archive of this journal is available at