Question

Explain Noonan's two arguments against the morality of abortion: probability and potential.

Answer 1

Noonan proposes human conception as the criterion of rights, and justifies it by appeal to the sharp shift in probability, at conception, of becoming a being possessed of human reason. Conception, then, is when abortion becomes immoral.

Two main arguments against the morality of abortion

1. Probability

Probabilities don't show humanity, merely meant to "buttress" standard: appears probabilities also meant to bolster the objective, genetic-human standard. A zygote has a higher probability of living than a sperm or ovum separately.
If one’s moral distinctions are not to appear arbitrary, then the distinctions should be based on changes in probabilities. Thus, one’s moral reasoning about the rights of the zygote are different than the rights of the sperm or ovum.

2. Potential

Once conceived, the being is recognized as man because he had man’s potential. Since it is immoral to take the life of another living human being, it follows that it is immoral to destroy the life of a being which has the potential to become fully human.