As rapid advances in nanotechnology are made, we must set guidelines to balance the interests of both human beneficiaries and the environment by combining nanoethics and environmental ethics. In this paper, I reject Leopoldian holism as a practical environmental ethic with which to gauge nanotechnologies because, as a nonanthropocentric ethic, it does not value the humans who will actually use the ethic. Weak anthropocentrism is suggested as a reasonable alternative to ethics without a substantial human interest, as it treats nonhuman interests as human interests. I also establish the precautionary principle as a useful situational guideline for decisionmakers. Finally, I examine existing and potential applications of nanotechnology, including water purification, agriculture, mining, energy, and pollutant removal, from the perspective of weak anthropocentrism using the precautionary principle.
