Where are Our Moral Centers?

Recently, I stumble upon a website dedicated to the education of people on animal cruelty. Although it is quite underdeveloped (I'm pretty sure it's a brand new website), it holds some quick facts that will easily leave an impression on someone. This made me think. Why would someone ever do such terrible things? Of course, there are many people who have done things that would astound others (Abu Ghraib, serial killers, genocides, etc.), but why would someone inflict pain upon a completely innocent being that is even incapable of communication? According to Kellert, S.R. and A.R. Felthous, there are nine reasons:

to control an animal

to retaliate against an animal

to retaliate against another person

to satisfy a prejudice against a species or breed

to express anger through an animal

to enhance one's own aggressiveness

to shock people for amusement

to displace hostility from a person to an animal

to perform non-specific sadism

Even so, it still manages to astound me how cruel people can be... How a person can actually retain pleasure from forcing two dogs to fight each other to the death... How a boy can giggle at a cat crying out while being burned to death... How a hunter can kill an endangered animal to make a fur coat... All of this is happening. It's all around us.