The argument from intrinsic value: A critique

In his recent book Abortion and Unborn Human Life, Patrick Lee develops an argument for foetal personhood based on intrinsic value. Lee argues that since the foetus is identical with the rational, self-conscious being who will exist a few years later, and since this rational, self conscious being indisputably is intrinsically valuable, therefore the foetus must already be intrinsically valuable; for nothing can come to be at one time but become intrinsically valuable at another. I show that this argument fails on two counts. First, the crucial premise that a thing's intrinsic value must derive from its essential properties is question-begging and devoid of support. Second, that premise is inconsistent with the pro-life position.