The Edge of Sentience: Risk and Precaution in Humans, other Animals, and AI

摘要

Where is the margin between homeostasis and suffering in humans, mammals, fish, invertebrates, and even AI? Demarcating where feelings of pain or pleasure begin and end is not simple. As an example, sentience could appear in complex machines and software, like AI. For Jonathan Birch, a philosopher of science and animal ethics, sentience includes a “capacity to have valenced experiences” (p. 1) ranging from distress to satisfaction. This definition helps identify welfare risks and assess ways to avoid inflicting gratuitous harm. That’s The Edge of Sentience in a nutshell; Birch takes readers on a compelling, engaging, and at times controversial journey through the sentient life of humans, a variety of nonhuman animals, and artificial intelligence. The word “edge” in the title is important in several respects. Birch is cautious not to make grand pronouncements; rather, in situations where evidence about sentience is not yet clear, there should be debate to negotiate disagreements. The way forward in terms of animal welfare and rights, Birch intones, is not by expert decrees but by crafting policy after discussion with average people on a public panel guided by experts. With its thoughtful framework and reasoned proposals, this book is valuable for students of ethics and animal studies, as well as lab researchers and policymakers engaged in fields from farming to software engineering.With human life, Birch discusses a case of unconsciousness where the patient, eventually revived, wondered why medical doctors presumed she’d feel no pain. A change of perception about sentience in humans, animals, and even machines is in order. We understand, mostly, the ethical implications of dealing with human pain, but what about mammals, fish, insects, etc.? For many invertebrate species, Birch concedes, sentience by human definition is still an open question. In decisions about animal welfare, often there’s a dividing line about any similarity between their suffering and ours. It is at this boundary, according to Birch, where our ethical decisions reside. He has experience, having advised the U.K. government about sentience in the invertebrate taxa cephalopod mollusks (e.g., octopuses) and decapod crustaceans (e.g., lobsters). Sentience, Birch says, is not detached from consciousness (i.e., it is not just an involuntary reaction). Most animals are not automatons, as Descartes asserted, and we are beginning to realize that some AI machines might experience sentience. Understanding sentience is important for ethical policy decisions. For example, he wonders how we regulate the use of human cells transposed into a computer as a neural organoid that could be sentient.Birch knows that sentience is not necessarily the result of complex sapience. Without evidence to the contrary, a being could have feelings without thought. Yet, he admits there has to be some consciously good/bad valence in the experienced feeling for sentience. Concerning phenomenal consciousness (i.e., the state of what it is like), he sees faults in its definition and use though it is a phrase worth developing. Birch insists on the term valence because, in reference to animals, it would be difficult to parallel all human emotions with theirs, except for basic ones like fear. Here is his policy advice about sentience regarding humans, animals, and machines: “Our precautions should be proportionate to the identified risks” (p. 18). Following John Rawls, Birch advocates open communication to air disagreement in search of principles about sentience. Psychological valence has, therefore, ethical considerations—how to minimize or eliminate pain. This stance is part of Birch’s proposals for not using non-human sentient systems, whether animals or AI, for human means without regard to their suffering.Birch does not accept the behaviorist posture that conscious experience produces a null set; it can impact behavior. We and other animals did not biologically evolve valenced sentience withou