(i) We should accept that early abortion is immoral only if we accept the "potentiality principle".
(ii) We should not accept this "potentiality principle".
In this essay, I will first discuss Tooley's arguments for these claims. After discussing the arguments, I will attempt to show that claim (i) is reasonable but claim (ii) is not. I will then propose a better argument for (ii) to strengthen Tooley's claims. To conclude, I will describe a typical objection to my argument and explain why this objection is invalid.
Tooley's Argument for Claim (i)
Tooley's argument for claim (i) stems from the conservative's assertion that adult humans possess a property which endows any organism possessing this property a serious right to life. From this claim, the conservative argues that any organism that has a potential to possess this property in the course of its development should also have a serious right to life. For simplicity, I shall call this argument the "potentiality principle". Tooley explained that this principle is very critical to the conservatives' argument because it allows them to defend their position without explicitly determining what properties a thing must possess to have a right to life. It is enough to define that adult human beings have this property and clearly they have a right to live. Therefore by the potentiality principle, it follows that the zygote of a human being must also have a right to life (Tooley, 1972). The potentiality principle is also very important according to Tooley because it not only provides support for the conservative's position
References: Tooley, M. 1972. Philosophy and Public Affairs. Vol. 2, No 1. Princeton University Press.