Humanity is failing at solving complex socio-ecological problems like global climate change, biodiversity loss and population growth. The existing 'sustainable development' paradigm and its reliance on trade-offs between the three pillars of environment, economics, and equity is not robust enough to maintain global carrying capacity. In this timely intervention, Thomas argues that the holistic and transdisciplinary thinking of four iconic American naturalists – Henry David Thoreau, Aldo Leopold, Rachel Carson, and Edward O. Wilson – can instead help to solve our biggest twenty-first century challenges by synthesizing values from four eras of cultural and environmental history.