The embryo, George and Tollefsen argue, is a whole being, possessing the integrated capability to go through all the phases of human development.
[This argument favours rather the opposite conclusion: since embryos have just the capability, they haven’t gotten through all the phases of human development, i.e., they are not completely human. A similar problem is recognised by the authors of the book, as we see below:]
An embryo has what it takes to be a free, rational, deliberating, and choosing being; it is naturally fitted to develop into a being who can be an “uncaused cause,” a genuinely free agent. Some will object, of course, that the embryo is only potentially human. The more precise version of this objection is that the embryo is human — not a fish or a member of some other species — but not yet a person. A person, in this view, is conscious enough to be a free chooser right now. Rights don’t belong to members of our species but to persons, beings free enough from natural determination to be able to exercise their rights. How could someone have rights if he doesn’t even know that he has them?
[Watch how this rights-and-free-agent talk entraps the authors:]
George and Tollefsen argue that the distinction between human being and person depends upon a contemporary philosophical prejudice that has no basis in reality. This “dualism” originated with Immanuel Kant, who held that free persons aren’t determined by inhuman or merely animal nature. Kant’s unempirical view is that there’s nothing natural about our freedom — and so there’s nothing natural about our rights, either. But contrary to Kant, we are, by our natures, the animals given the capabilities for personal freedom; we are, so to speak, hardwired as social animals, given the responsibility to live and act well in light of the truth. Human nature isn’t an oxymoron. The authors praise Kant, reasonably enough, for wanting to defend our absolute freedom, but they criticize him for being hopelessly vague about that freedom’s foundation. The attempt to detach the moral category “person” from the natural category “human being” produces arbitrary, rationally indefensible results. Kant’s dualistic way of thinking would deny personhood not only to, say, people with fairly advanced Alzheimer’s, but also to newborn babies, who are less self-aware than dogs.