Constant disputes concerning the concept of sentience result from an extremely difficult topic of considerations, which is the comparative approach to the experiences, conscious states and cognitive processes of humans and non-human animals. There is a lack of interdisciplinary agreed positions on which cognitive systems we consider to be already sentient and which not yet. As a result, significant differences appear in the analyses and definitions of the sentience phenomenon. Scientists and experimenters have not developed a single, common explanation of the phenomenon of sentience which would include philosophical reflection, neurobiological experiments and psychological observations. A brilliant answer to all the above problems is Jonathan Birch’s book. It contains not only in-depth analyses of various positions on sentience, but also references to real political actions and everyday consumer practices.