The main theme of the ninth volume of Eco-ethica is “Engagement and Philosophical Responsibility.” A number of the essays included are revised papers from the 39th International Symposium of Eco-ethica, which was held from November 6 to November 10, 2019, at the Sigtuna Foundation (Sigtuna, Sweden), north of Stockholm. Contributors in English or French include Robert Bernasconi, Patrice Canivez, Pierre-Antoine Chardel, Zeynep Direk, Divya Dwivedi, Manuel B. Dy, Jr., Noriko Hashimoto, Peter McCormick, David M. Rasmussen, Jacob Dahl Rendtorff, Göran Rosenberg, Jayne Svenungsson, and Bengt Kristensson Uggla.