In philosophy, the Law of Identity holds that something is what it is. It's identity remains the same over time despite changing properties. I show how this argues for the humanity of the unborn. I also explore the liability of defining humans in terms of their properties rather than their kind, and correct a misunderstanding of human development that sees humans as being constructed rather than built. Humans are not the kinds of things that emerge only after a number of pieces are assembled together, but are present from conception. Humans build themselves from the inside out toward maturity.