Giving animals their due: the argument from "marginal cases"

 05_Tanner.indd (environmentandsociety.org)

Reductio ad absurdum version:

1. In order for an entity to acquire basic moral status – to matter morally, to be one toward whom we have direct moral duties -- it must possess capacity C (for example, language, or moral agency, or a complex sense of self, etc.).

2. Nonhuman animals do not possess C.

Therefore,

3. Nonhuman animals do not matter morally.

But,

4. Some humans (infants, young children, the mentally impaired, etc.) do not possess C.

Therefore,

5. Some humans do not matter morally.  (An “absurd” result.)

Formal contradiction version:

1. In order for an entity to acquire basic moral status – to matter morally, to be one toward whom we have direct moral duties -- it must possess capacity C (for example, language, or moral agency, or a complex sense of self, etc.).

2. Nonhuman animals do not possess C.

Therefore,

3. Nonhuman animals do not matter morally.

But,

4. Some humans (infants, young children, the mentally impaired, etc.) do not possess C, and

5. All humans matter morally.

Therefore,

6. It is not the case that, in order for an entity to acquire basic moral status – to matter morally, to be one toward whom we have direct moral duties -- it must possess capacity C (for example, language, or moral agency, or a complex sense of self, etc.).  (That is, (1) is false.)

(It may be, for example, that basic moral status accrues to those who can consciously suffer or are "subjects of a life.")