Problems with this approach
There are several problems with this way of looking at the moral status of animals:
How can we understand the mental landscape of any other sentient creature?
- by inference from the animal's behaviour or physical structure
- by imagining what the creature is feeling
How can we tell whether an animal has a preference to continue living?
- we probably can't
- an animal's attempt to avoid being killed painfully will appear exactly the same to us whether the animal is attempting to avoid being killed or whether it is merely attempting to avoid a painful experience and has no concept of death
How do we compare the relative interests of different animals in the same category?
Interests, needs and wants come in different varieties with different weights; how do we include the relative weights of different interests when we are faced with moral choices?
Weights of interest
- Basic interests: interests concerned with survival.
- Serious interests: needs - interests that have a major effect on the animal's quality of life.
- Trivial interests: wants that are nice to have satisfied, but the animal can manage perfectly well even if they are frustrated.
How do we judge an issue where satisfying the trivial interests of a higher animal frustrates the basic interest of a lower animal? For example: to protect the basic interest of a fish to survive, a human's trivial wish to eat it must be frustrated.
What about the problem of human animals that are not self-aware?