The Second Variation builds on the First:
| Step 1: | 1 | Every fetus is a person. | |
| 2 | Every person has a right to life. | ||
| Therefore | 3 | Every fetus has a right to life. | 1&2 |
| Step 2: | 4 | No being with a right to life may be killed unless it is a fetus, the pregnant woman's life is threatened by its development, and she performs the abortion. | |
| Therefore | 5 | No fetus may be killed unless its development threatens the pregnant woman's life and she performs the abortion. | 3&4 |
Suppose Smith and Jones are stranded out in the cold and only Smith has a coat. Smith has a prior claim to the coat, since it is his. Surely we would not be justified in saying: we can't make any decision between Smith and Jones as to who should have the coat. After all, Smith does have a prior claim to the coat. Now suppose Jones overpowers Smith and takes his coat. Consider the following argument:
| A | 1 | If Smith has a prior claim of ownership to his coat, then it is morally right for someone in authority to return Smith's coat. | |
| 2 | Smith has a prior claim of ownership to his coat. | ||
| Therefore | 3 | It is morally right for someone other than Smith to return Smith's coat. | 1&2 |
| B | 1 | No being with a right to life may be killed unless it is a fetus, the pregnant woman's life is threatened by its development, and she performs the abortion. | |
| 2 | If (1) then it is morally wrong for anyone other than the pregnant woman to perform an abortion. | ||
| Therefore | 3 | It is morally wrong for anyone other than the pregnant woman to perform an abortion. | 1&2 |
| C | 1 | PA: If one of any two actions which are similar in all morally relevant respects is morally right, then so is the other, and if one of any two actions which are similar in all morally relevant respects is morally wrong, then so is the other. | |
| 2 | The act of someone other than Smith returning Smith's coat is similar in all morally relevant respects to the act of someone other than the pregant woman performing an abortion. | ||
| 3 | It is morally right for someone other than Smith to return Smith's coat. | ||
| Therefore | It is morally right for someone other than the pregnant woman to perform an abortion. | 1,2&3 |
So we have it by Arguments A and C that it is morally right for someone other than the pregnant woman to perform an abortion. But notice that if so, then it's not the case that it is morally wrong for someone other than the pregnant woman to perform an abortion. So the conclusion of Argument B is false. But Argument B is valid, so at least one of its premises must be false. Since premise (2) of Argument B seems correct, it must be the case that premise (1) is false. That is to say, it is not the case that:
- No being with a right to life may be killed unless it is a fetus, the pregnant woman's life is threatened by its development, and she performs the abortion.