@L1n1o,
L1n1o wrote:So from the short argument you stated, a valid question to ask would be why should only rational beings have rights, why not animals? why not plants?
Putting my Utilitarian hat on, I think of moral rights as practical, cultural tools for increasing the total surplus of happiness over suffering in this world. Plants can't experience either, so from my perspective they ought not have rights. Nonhuman animals can experience both to various degrees. For some animals, like sponges, this capability is near-zero. For others, like the Great Apes, it is near-human. Accordingly, animals should have rights of various extent, proportioned to their capability to experience pleasure or pain.
Humans, as a rule, merit an even more extensive set of rights than nonhuman animals, because humans are rational. This justifies extended rights because rationality decreases the transaction costs around our rights, and greatly increases their benefits.
Rationality decreases the transaction cost of enforcing human rights, because human individuals can usually enforce their own rights in a straightforward manner. Nonhuman animals, by contrast, must depend on lopsided, expensive methods involving humans. In addition, rationality and self-awareness increase the benefits of rights: Unlike nonhuman animals, we routinely experience happiness and suffering second-hand by empathizing with others and by imagining our own futures.
With all this in mind, I agree with the original post that humans should have more extensive rights than other animals, but disagree that animals have no moral rights at all.