动物能否感觉疼痛不是一个易于回答的问题。人类仅对自身承受的痛楚有直接意识。我们甚至对别人痛觉的认识也只是根据她们的描述或次之——他们的行为得出的推论。动物不能告诉我们它们的感受。当然我们可以研究它们怎样对使人产生痛觉的刺激物所作出的身体反应;这是我们经常做的。当刺激物作用于动物时, Whether an animal can feel pain is not an easy question to answer. Humans have a direct sense of their own pain. We even know the pain of others just based on their description or second, their inference. Animals can not tell us how they feel. Of course, we can study how they react to the bodily irritating stimuli that we often do. When irritants act on animals,