Every ought implies an is. What does this mean and why does it matter? It means that for every ought statement (“you ought to eat your vegetables”), there is a rule, code or law behind it with authority that gives it weight—that makes it mean something. The reason it matters is because if there is not an authority behind the ought, then there is little reason anyone should pay attention to it. Ought statements imply a religious belief (though not necessarily theocentric), that whatever is said is based on an ultimate truth reality.
Take, for example, the statement, “you ought to be able to choose to have an abortion at any time for any reason.” What is the ultimate truth claim behind that statement? I believe the ultimate reality implied in that statement is an egocentric belief that my ability to choose what I want to do trumps any other ethical reality. When someone protests and claims that the sanctity of human life is more paramount than a person’s ability to choose to have an abortion, the response often is (as Yale School Law professor Arthur Leff stated) “sez who”? In order for there to be an evaluation of what is more paramount, there must be an “evaluator,” an “unjudged judge,” an “uncreated creator of values.” Leff goes on to state that, “it looks as if we are all we have. … Only if ethics were something unspeakable by us, could law be unnatural, and therefore unchallengeable. As things now stand, everything is up for grabs.”
Leff’s worldview—and the worldview in general that believes “we are all we have”—is existential in that it absolutizes human subjectivity and makes it “the ultimate source of ethical norms” so that any external, objective norm for ethical decisions is to be avoided. The French existentialist Jean-Paul Sartre, whose notion that “being arises from choices, rather than choices being determined by it,” recognized that life is utterly meaningless and all we can do is define ourselves in the moment, “just do.” The consequence of this worldview is the belief that we are radically free and not “subject to any authority outside of ourselves,” a human being exists only pour soi—for himself. If we take this worldview to it’s logical conclusion, our only choice is to live “authentically” expressing our freedom, often overturning conventions, and doing things occasionally that are even morally repugnant. This is, I believe, the ultimate truth reality behind the “pro-choice” position, for it denies the existence of an “uncreated creator of values.” and allows each person to define his choices according to the impulse of the moment. As Arthur Leff finally concludes despairingly, “There is in the world such a thing as evil. (All together now:) Sez who? God help us.”
 Arthur Allen Leff, “Unspeakable Ethics, Unnatural Law,” Duke Law Journal, no. 6, (December 1979): 2, accessed January 22, 2018, https://scholarship.law.duke.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=2724&context=dlj;
 Ibid, 2.
 Ibid, 21.
 John M. Frame, The Doctrine of the Christian Life, Theology of Lordship (Phillipsburg, NJ: P&R Publishing, 2008), 76.
 Tim Sansbury, “Ethics,” Lecture 8, (Knox Theological Seminary: 2017).
 Frame, The Doctrine of the Christian Life, 85-86.
 Ibid, 88.
 Leff, “Unspeakable Ethics, Unnatural Law,” 21.