Abortion

John T. Noonan makes the argument that the jump in probability for a fetus' coming to term, at a specific point in the development of the fetus, has an important implication for the humanity (personhood) of the fetus. He bases this argument on the reasoning that "life itself is a matter of probabilities, and most moral reasoning is an estimate of probabilities." He goes on to state that his argument in which a fetus has an implication for the humanity of the fetus is strictly an "appeal to probabilities that actually exist." To demonstrate his point concerning probabilities he uses an analogy. The analogy he uses is of a man who shoots into the bushes because of movement in the bushes. If the chances of this movement in the bushes being a man were 200 million to one, then no one would think anything of him firing away into the bushes. However, if the chances are 4 out of 5 that the movement is a man, then you would not be justified in firing into the bushes. He uses this analogy to relate it to the development of a baby. When a male ejaculates he emits about 200 million spermatozoa. Of these 200 million, only one single spermatozoon has a chance to develop into a zygote. Noonan says that therefore, if one spermatozoon is destroyed than you're only destroying a being that had a one in 200 million chance of ever developing into a reasoning being. This would be similar to the case of shooting into the bushes when there is a one in 200 million chance that the movement is that of a man. On the other hand, if a fetus is destroyed, then you're terminating a being that had "an 80 percent chance of developing further into a baby outside the womb who, in time, would reason." This would be similar to shooting into the bushes when the movement has a 4 out of 5 chance of being that of a man. The probability of the baby becoming a full being of reason drastically changes from a single spermatozoon (1 in 200 million) to a fetus (4 out of 5). This probability change is important because it leads you to believe that aborting a fetus is wrong because of the high probability it has of becoming a being of reason.

Judith Jarvis Thomson offers a rather interesting analogy to an unwanted pregnancy. Thomson begins her analogy with the hypothetical situation of waking up and finding oneself wired by their