A reflexive view on the discipline of psychology implies that the discipline’s models and theories not only describe or predict but also shape human subjectivities and actions. In today’s situation, where human activities drive an immense loss of biodiversity and natural areas, it is thus crucial to challenge the ways psychology theorize humans’ relations to nature and other species. Within ecopsychology, a key assumption is that humans are alienated from nature, leading to both individual suffering and environmental destruction. Similarly, preventive psychology’s models typically include natural conditions such as access to green spaces and clean air and water. Thus, both ecopsychology and preventive psychology illustrate how nature is indeed integrated into psychological models of human development and quality of life. However, building on the critical assumption that theories shape our subjectivities, it is still necessary to investigate how the more dominant mainstream theories may be developed to re-theorize our relations with nature and other species. In this paper, I argue that Bronfenbrenner’s ecological systems theory is a good candidate for such a theory. The aim is to illustrate how this theory may be developed by integrating geosystems across the theory’s microsystems, mesosystems, exosystems, and macrosystems. For such re-theorizing to be successful in shaping subjectivities where humans are less alienated from nature and nature is understood as something more than a provider of ecosystem services, I argue that the scientific language of disciplinary psychology is insufficient. Instead, the transformative potential of re-theorizing will be more successful if it is inspired by how relations between humans, nature, and other species are explored through the language of contemporary poetry.