The opinions regarding animals and their rights greatly vary. To some, animals have no rights and are merely a form of property that exists only to fulfill human needs. To others, they are creatures that can be used or owned by people, but which also have feelings and are not to be subjected to needless suffering or pain. (Some would say that people with this belief are animal welfare, as opposed to animal rights, advocates.) Finally, there are those who believe that at least certain animals, such as those with sophisticated levels of intelligence and emotions (including nonhuman primates such as monkeys and chimpanzees), are not property at all nor meant to be utilized by man in any way. Such people believe that these animals are entitled to fundamental moral and legal rights that are currently accorded only to humans.

The animal rights movement includes many...