* Emphasis on the development of the whole person: Spiess believed that physical education should contribute to the overall development of the individual, encompassing physical, mental, and moral aspects. He saw gymnastics not just as a way to build strong bodies, but also to foster discipline, character, and social skills. This was a significant departure from the primarily military-focused gymnastics systems of his predecessors.
* Development of a systematic program: He designed comprehensive gymnastics programs that were age-appropriate and progressively challenging. His systems incorporated a wider range of activities than previously seen, including games, dances, and outdoor activities alongside more traditional gymnastic exercises. This was crucial in making physical education more accessible and engaging for a broader population.
* Pedagogical approach: Spiess emphasized the importance of qualified teachers and structured lessons. He advocated for teacher training and developed instructional methods focused on proper technique, safety, and the educational value of physical activity. This laid the groundwork for the professionalization of physical education.
* Influence on the spread of gymnastics: Although he didn't travel extensively, his writings and the training of teachers based on his methods spread his influence across Germany and beyond, significantly impacting the development of physical education in other countries.
In essence, Spiess's contribution was to transform gymnastics from a narrow, specialized activity into a more broadly conceived and pedagogically sound component of education, emphasizing the holistic development of the individual through physical activity. He is considered a key figure in the transition from earlier, more militaristic forms of gymnastics to the modern field of physical education.