She suggests that unless there is a divine entity, the concepts such as “morally ought,” “morally obligated,” “morally right,” cannot be justified. A moral theory, she holds, requires a legislator to legislate what is morally right. In her view the modern ethical philosophers are making a mistake when they talk about actions that are “morally right or morally wrong,” but fail to define the entity which promulgates the moral law. According to Anscombe, without the idea of divine, the concept of “morally right and morally wrong” is meaningless. She posits that the secular philosophers should use terms such as “untruthful,” “unchaste,” “unjust.”
“I should judge that Hume and our present-day ethicists had done a considerable service by showing that no content could be found in the notion "morally ought"; if it were not that the latter philosophers try to find an alternative (very fishy) content and to retain the psychological force of the term. It would be most reasonable to drop it. It has no reasonable sense outside a law conception of ethics; they are not going to maintain such a conception; and you can do ethics without it, as is shown by the example of Aristotle. It would be a great improvement if, instead of "morally wrong," one always named a genus such as "untruthful," "unchaste," "unjust." We should no longer ask whether doing something was "wrong," passing directly from some description of an action to this notion; we should ask whether, e.g., it was unjust…”
Modern Moral Philosophy” has influenced the development of virtue ethics in the past few decades. It is notable that the term "consequentialism" was first coined by her in this essay. She uses this term to describe the central errors in secular moral philosophies, such as those propounded by Mill and Sidgwick.