Christopher McKay strikes a position between these two, what may be termed weak ecocentrism, proposing that an entire biosphere of alien life, even if only microbial life, has far more value than individual microbes, and should not be subject to interference by Earth life. However, he also proposed that it would be valuable and desirable to terraform a planet to nurture the alien life, to allow it to thrive as well as to exhibit a broader range of behavior for scientific study, and that such activity is ultimately justified by the utilitarian value to humans of being able to study and appreciate the still somewhat undisturbed alien life. McKay put his views in these words: