Book excerpt: The Predictive Processing Theory of Mind is a recent theory developed by philosophers, cognitive scientists, and neuroscientists about the nature and function of the brain and its role in creating the conscious mind that we humans, and perhaps some non-human animals, have. The authors that advanced those lines of research believe that there is a fundamental idea that has been overlooked in the research done about the brain until the present: that the brain is a prediction machine with the function of creating hypotheses about the causes of our sensory signals and predictions of possible future sensory signals. Moreover, the internal models of the world created this way are constantly challenged by incorporating the errors of the previous models into new models. From this point of view, the brain's work could be described as a process of making predictions about the upcoming sensory data based on its best current models of the causes of those data. This book intends to critically analyze this theory and its subsequent theoretical and empirical consequences. To achieve that, the volume brings together some of the best experts on Predictive Processing – such as Thomas Metzinger, Wanja Wiese, or Mark Miller – with the goal of presenting some of the advantages of this approach but also some of its caveats.