As will become apparent from the following discussion, the debate over animal sentience has, like a growing number of present-day issues, become rather polarized.
A case in point was the recent Annual Meeting of the Canadian Veterinary Medical Association (CVMA) where a summit was held called "Animal Sentience: What Does It Mean, Why Is It Difficult to Define, and What Effect May It Have on the Veterinary Profession?" Dr. Tim Arthur, the CMVA’s newly elected president, told me this was the first time this topic was discussed at one of their conventions. He directed me to the recently issued CVMA Position Statement on Animal Sentience which states, “Sentience in this document means having the capacity to experience positive and negative feelings such as pleasure, excitement, fear, hunger, pain, and distress ... The CVMA holds that many species of animals are sentient.”
Professor Georgia Mason, in the Department of Integrative Biology, at the University of Guelph was one of the speakers at the conference. I contacted her to seek her views on animal sentience.
She said she fully supported the CMVA’s position paper. In response to my question, she explained the difference between sentience and consciousness by saying that sentience is a type of basic consciousness. “It is the ability to feel or be aware, sometimes described as the ‘what it is like’ aspect of a state. Sentience does not imply self-awareness, theory of mind, or anything else 'higher order' (i.e. complicated/cognitively sophisticated.”
Mason uses sentience to refer to just the sub-type that is most ethically relevant, emotions, an animal's capacity for pain or other forms of conscious affect. Mason has referred to measures such as discriminating between stimuli, displaying Pavlovian conditioning, and even learning simple instrumental responses as “red herrings” that should not be used to infer sentience because they are........