In the past, most religions emphasized spiritual life and human ethics. Due to the fact that the study of environmental ethics is becoming popular, religious studies scholars have begun to consider whether there are any environmental thoughts in existing religious ethics or precepts. This study concerns two major world religions, Buddhism and Christianity. It attempts to look into their abundant ecological thought which has gradually developed in their ideology. I find the philosophical foundations of the two religion's ethics to take a gnoseological and an ontological approach. It seems that from these approaches, both religions have the basis for environmental theories. Whether one starts from the ”three learnings” of Buddhism or from Christianity's ”theological virtue”; the fundamental precepts of both religions not only closely relate to current environmental ethics, but are also helpful in establishing environmental practices. They become meaningful in today's world in this manner. I finish this paper by synthesizing all the fundamental precepts of religious ethics and proposing six principles of environmental ethics to related experts.
