The historical period of civilization coincides with the period in the history of the planet when nature has been artificially controlled and manipulated to a great degree. However, the current ecological crisis caused by human civilization paradoxically also threatens human beings. The teaching of mutual causality shows us the need to recognize our interconnectedness and the necessity to adopt a lifestyle compatible with all living things. Buddhism teaches us that human ignorance is the primary cause of the reduction of biodiversity on the planet, destruction of the natural ecosystem, and the disruption of human habitats. Observance of the precept to not kill is a practical and compassionate life choice which can support and secure biodiversity. Such a life choice represents the path of an active practitioner rather than one who makes speech but fails to follow through with action.