This paper argues that those that subscribe to “Biocentrism”, specifically the Biocentrism argued for by Paul Taylor, ought to adopt “Ontocentrism” instead. Biocentrism, the theory that all and only living things are morally considerable, fails to account for important moral differences between living things. It cannot justify, without ad-hoc addition, the intuition that a man is worth more than a pig, and a pig is worth more than a mouse. It similarly fails to account for the status of larger systems such as ecosystems, and lastly it fails to account for the status of non-biological entities and artificial life. Ontocentrism, the theory that all existing things, broadly construed, are morally considerable, ought to be adopted because it can account for these things without being ad-hoc and arbitrary.