The phenomenon of illegal bear bile trade has aroused public concern in recent times. Driven by the demand for bear bile in medical use, a large number of bears are captured from the wild, locked up in the cage and forced to endure the torture of bile collection without anaesthetic. A true story from Hubpages (2011) describes how a mother bear killed her baby and committed suicide. The mother bear believed that it would be better if her child were to die rather than to suffer such unrelieved distress. This heart-breaking story should have awakened people to consider whether it is right to do whatever we want on animals. In reality, animals should have their own right since they are sentient beings and equal to human beings as subjects-of-a-life, and it is unjust to inflict pains on nonhuman animals.
Some people believe that animals are unconscious creatures and they are biologically incapable of feeling pain. This fallacy may be attributed to the fact that animals have no language and they are unable to express through language when they are suffering. However, instead of communicating with others in human language, they use gestures, facial expressions or vocalizations as human infants do to claim that they are fearful or painful. Hence, it is self-deceiving to insist animals are not sentient when hearing their painful screams, moans or watching they are miserably clutching their own bodies. In the meantime, tracing human evolution to its roots, it can be identified that human beings evolved from other species. Sarjeant (1969) demonstrates that animals possess anatomical complexity of the cerebral cortex and neuroanatomy, which is identical to human’s nervous system. It is common for mammals and birds to feel pain since they have more developed nervous systems and their feelings are located in the diencephalon. Therefore, it is immoral and merciless to inflict excruciating pain on the innocent...