This article challenges an important argument in the abortion debate, according to which at least early abortions are acceptable because they do not terminate the actual existence of something of moral significance (i.e., a ‘person’), but rather prevent a potentially significant entity from becoming actual, which happens whenever one uses contraceptives. This article argues that insofar as we see something as morally significant or valuable, we tend to think it wrong to deliberately terminate its actual existence and to deliberately prevent a corresponding potential entity from becoming actual, a principle I call the ‘Inverse Proportional Value Principle’. After defending this principle and showing it to oppose the idea that abortion is acceptable since it simply prevents the existence of something of moral worth or value, I show this principle to sanction some abortions, given that the entity which stands to result from a pregnancy is sufficiently lacking in value.