This essay polemicizes with a number of historians who claim that the European Renaissance has either “failed” or “continues to recede from us at an accelerating rate” (Burke 1998: 41; Barzun 2000; Bouswma 2002). I explore and revalue the ideas and representations of Renaissance humanism and the way they become manifest in the work of Leonardo da Vinci. I argue three main points: Firstly, that there is a fascinating, and much underestimated, ecological strain in Leonardo’s opus, a view of relationship between humans and nature, which has a bearing on a paradigm shift required by the current environmental and social crisis. Secondly, in the project of re-imagining a sustainable future, there is much to learn from the way in which a small and subversive community of Renaissance umanisti managed—against all odds—to forge a ground-breaking ethical vision which became the foundation of Western modernity. Finally, both Leonardo’s legacy and a reinvention of humanity and nature in the ideas of the Renaissance writers and thinkers, draw attention to a unique code of “eco-humanism”—a value platform emphasizing human dignity, nature’s autonomy and authority, the importance of free inquiry and dialogue, as well as the codex of limitations to human pursuits.