The study aims to determine the role of a teacher’s personality in solving moral and pedagogical problems arising in the process of teacher-student relations in the educational sphere of Russia in the early 20th century by conducting a theoretical analysis of individual documentary fiction texts by K. G. Paustovsky in the genre of documentary prose. The paper substantiates the importance of the priority spiritual and moral principles and values of Russian pedagogy and psychology as the basis of the traditional knowledge paradigm of education, actualizes their relevance in modern Russian theory and practice. The study is original in that it is the first to reveal the role of a teacher’s personality primarily as an educator and bearer of moral universal values in the traditional knowledge paradigm of education based on K. G. Paustovsky’s documentary fiction stories about the teacher-student relations in the educational sphere of Russia in the early 20th century. In addition, the paper determines the importance of a teacher’s personal self-esteem (professional reflection) and their individual threshold of tolerance and responsibility for the process of forming the personal image of pupils, humanistic qualities and psychological characteristics of students. As a result, it was found that an essential factor of success in solving moral and psychological problems in the system of teacher-student relations in both traditional and modern humanistic paradigms of education is the personality of a teacher, their “human factor”. The professional reflection of a teacher, which is their personal self-assessment manifested in psychological, creative, moral and mental abilities at an active and interactive level to influence the spiritual world of a pupil, creates conditions for the movement of the educational process towards the creative self-expression of a student’s personality. A teacher’s ability to correctly assess and take into account students’ personal and psychological characteristics ensures the formation of conditions for pupils’ personal growth, their values and worldview orientations.