I see plenty of reason in ZPHOBIAZ’s argument that animals are too simple to be grouped with us, and plenty is Curtis Lemay’s argument that humans have souls while animals don’t, but the best argument is just good sense. Humans are humans. Animals are animals. Animals are not grouped with humans because animals are not humans. Humans can read, write, talk, do math, study the past, analyze the present, theorize about the future, think abstractly, philosophize, follow God, make art, educate others and themselves, etc… Animals can’t do any of those things. While a few people will claim that they view humans as a type of animal, they’re still willing to walk through doors that say “no animals allowed”. Everybody understands the difference even if they say they don’t.
We make moral decisions based on sense and reason. (Certainly not because of anything biologically ingrained, since plenty of people have been willing to kill their fellow countrymen, or even their family members.) Sense and reason say that animals should not be included in the group of humans. In fact, for the purpose of a working morality, they can’t be. You could say that chimpanzees are now the moral equivalent of humans, but it wouldn’t mean anything. You might convince humans not to engage in violence towards chimps, but you can’t convince chimps not to engage in violence towards humans. Adults chimpanzees are instinctively violent. Unless you believe that humans are morally required to submit to being killed by chimps, you have to do something to stop the chimps from attacking. You could move the chimps a long way away from humans, kill the chimps, or put the chimps in cages. But all three options mean treating chimps as inferior to humans. So in short, we have to treat chimps as inferior to humans because they are inferior to humans.
Treating things as they are does not mean treating things badly. By any reasonable measure, recent trends in thought have been bad for animal rights. While philosophers in academic departments churn out books and papers purporting to prove that animals have rights, the treatment of animals has gotten worse, as anyone who’s been to a slaughterhouse or factory farms can testify. Animals would be better off if we jettisoned all the modern, philosophical garbage and went back to the sensible beliefs that humans are the capstone of creation and as such, have a responsibility of stewardship for the lower levels of creation including animals.
When civil rights leaders said that black people were equal to white people, they were right. When members of PETA and other nutters say that animals are equal to people, they are wrong. Anything that a typical white person can do, a typical black person can do. But the vast majority of things that a person can do cannot be done by the most intelligent chimpanzee on the planet.