This article considers the question of why it is difficult to adopt a One Health approach to optimizing health despite its importance and argues that ecological thinking is necessary for the practice of One Health. Although from an environmental perspective humans and non-humans co-exist in a complex set of relationships, social systems tend to treat humans, animals, and the environment as distinct entities. Accordingly, Niklas Luhmann attributes ecological problems, at least in part, to society itself and not merely to political or economic failures or moral shortcomings. However, while social systems such as the economy, science, politics, and education, are in an important sense closed, they can also be responsive to each other through One Health communication. Above all, in order for One Health to operate within these social systems there is a social need for ecological thinking that the human body is inseparable from the material world, biological life, ecosystems, biomaterials, and human-made materials.