The idea being debated
Another very common justification is that humans have abilities animals don't have. For example: reason, language, a sense of right and wrong, a sense of justice, culture. Because of that, only humans would deserve respect, or they'd deserve more of it.
You've probably heard sentences like these:
- "Animals don't have rights because they don't have duties."
- "Animals don't understand what justice is."
- "Animals don't fight for their own rights."
Some people also talk about relationships: humans have bonds of love, solidarity, or politics with each other, so they should favor one another.
Problem 1: many humans don't have these abilities
Babies don't know what justice is. Neither do people with certain mental disabilities. Nobody thinks that makes it okay to use them in experiments or as food. So these abilities can't be the reason for respect.
The same goes for relationships: some humans are alone, with no family and no friends, and they still matter.
Problem 2: it doesn't explain why it would matter
Being good at math or speaking a language doesn't change how much a burn hurts. The argument doesn't show the link between having these abilities and deserving not to be hurt.
Problem 3: there are reasons to think it doesn't matter
Think about why we shouldn't harm a baby. It's not because the baby knows philosophy. It's because the baby can suffer. That same reason applies to a dog, a chicken, or a fish.
In short
- Many humans don't have reason, language, or a sense of justice, and they still matter.
- Intelligence doesn't change how much pain counts.
- What counts for not being hurt is being able to feel.