Moral standing is acknowledging the moral significance that an entity possesses so that its interests and welfare are considered when we discuss ethics. The history of ethics is often associated with discussions on extending moral standing. Recent literature in ethics tries to extend moral standing beyond the human species. Concerns have been raised by moral thinkers like Peter Singer and others, who consider certain actions by human beings on animals as being unethical. Peter Singer in his work Animal Liberation, In Defense of Animals, Practical Ethics and in many other works as well argues that like human beings, animals also possess moral standing and some or most of our actions towards animals leads to an unequal treatment on those beings. He justifies extending ethical considerations to animals on the principle of sentience. Sentience is the capacity of the being to experience pain or suffering. The objective of this study is to see if Singer’s principle of sentience does really extend moral standing. In this paper, we critically analyse the logical outcome of applying his principle to humans and animals. Based on the results of our study, we claim that instead of extending moral standing, Singer’s principle limits the scope of moral consideration. Singer’s theory may inevitably result in limiting moral standing only to living members of the human species and may set aside from moral consideration potential human beings such as the human fetus.