Philosopher Michael Tooley developed a thought experiment to try to show that potential personhood ought not count. This is the thought experiment:

Imagine that we have a newborn kitten that we can inject with a special chemical which would initiate a causal process that would lead to it eventually developing into a cat possessing all the psychological capabilities that are characteristic of adult human persons.’

(1972, ‘Abortion and Infanticide’, Philosophy and Public Affairs Vol 2 No 1: pp.37-65)

Tooley claims:

(i) Once injected there would be no morally significant difference between the cat that developed and a human person, and so we would have to ascribe a serious right to life to the cat, if we are to ascribe it to the human person.

(ii) It would not be seriously wrong to refrain from injecting the kitten with the special chemical (and even to kill it instead) – it does not currently have personhood potential.

Paraphrase: The fact that one could transform a kitten into a being which would develop the properties required for a serious right to life, does not mean the kitten has a serious right to life even before it has been injected. It is not seriously wrong to refrain from initiating this causal process. Nor is it seriously wrong to interfere with it to prevent the development of the properties in question, including by killing it.

By analogy it would not be wrong to kill a human fetus. The potentialities are the same. Both are potential persons. The only difference is that the human fetus had potentiality from the beginning of its development, while the kitten has it only from the time it was injected.

Questions:

(i) What do you think of this thought experiment?

(ii) Do you agree that the kitten is a potential person in the same way as a fetus is a potential person?

(iii) Tooley says that to defend the potentiality principle would require us to say that in a world in which kittens could be injected to become rational animals, it would be seriously wrong to kill kittens. He doesn’t think there is much to be said for that view. Do you agree?