Thinking Journey is introduced as a mode of science instruction based on a specially designed discussion between students and teachers in the context of an imaginary journey. The paper elaborates the rationale of this mode and its specific features: enculturation into science, analytical observation, multiple perspectives of the subject and environment, hypothetical thinking, and active interaction between the teacher and students. The role of the teacher is argued to be mediation of knowledge. The method was applied for teaching the concept of gravitation and its relationship with up-down direction. Positive results of the application suggest that the TJ mode of teaching is effective in teaching various student populations.