[Excelsior]

(12-03-2011 09:39 PM)ao85 Wrote:  

What is the philosophical justification for animals having less rights then humans?

Personhood.

Most animals are simply not self-aware, not self-reflective, have no true notion of past/future, no concept of rights/duties/morality, or any of the other things that make a human a person, and not just another animal. They are also incapable of understanding or articulating any of these concepts-they operate on instinct.

A person is distinguished by high intellect, self-awareness, self-reflectiveness (the ability to rationally consider his/her actions within the greater context of the world around them), belief in morality/duty (beliefs that make civilization of any kind possible) and the ability to transcend mere instinct (at times even going against it due to aforementioned belief in morality/duty). A person can also articulate and understand all of these concepts.

Humans are the only creatures on Earth that consistently meet the definition of personhood. One could argue that some outliers within the human populace (ex: fetuses and some of those who suffer from mental retardation) do not meet the definition of personhood, but their intricate association with humanity (fetuses and even embryos become persons and are essential portions of any person's life cycle and even the mentally deficient are human and carry traces of human personhood lacking in 99% of animals, with the IQs [though low by human standards] to prove it) causes them to be treated as persons in most cases anyway.

The only animals that really should be considered to have reached a stage even remotely close to personhood are elephants, cetaceans (whales, dolphins, porpoises) and some great apes (like our closest cousins, chimpanzees) due to the uniquely advanced intricacies of their social structures and high intelligence.