What sentience is
If what matters is being able to be harmed or helped, we need to understand what makes someone able to be harmed or helped. The answer is sentience.
A sentient being doesn't just react to the world like a machine. For them, there is something it's like to feel: hunger, fear, pain, cozy warmth, joy.
Good and bad experiences
Another important part: these experiences can be positive or negative. This has a technical name, valence. A pain is bad for whoever feels it. Being petted is good.
A rock doesn't feel anything, so nothing can be good or bad for it. But for a dog, things can go well or badly.
Two ways to harm someone
A sentient being can be harmed in two ways:
- when something bad happens to them (for example, when they suffer);
- when they're kept from having something good (for example, when they die and lose all the good things they would still have lived).
Two ways to help someone
And they can be helped in two ways:
- when something good happens to them (for example, they feel pleasure);
- when something bad is prevented or eased (for example, when a pain goes away).
Why this matters
It's because they're sentient that animals need consideration. And that's why we need to find out which beings are sentient: they're the ones who can be helped or harmed by what we do.
In short
- Sentience is the ability to have experiences, good or bad.
- Only sentient beings can be harmed or helped.
- Harming means causing something bad or taking away something good; helping is the opposite.