After a long discussion process, the European Union’s Artificial Intelligence Act will soon assume the position of a pioneering step towards the regulation of artificial intelligence in a comprehensive way. Among the prohibited uses of this technology are subliminal techniques, that is, techniques aimed at the perception of stimuli captured by the senses under the threshold of consciousness. These techniques can result in the manipulation of the minds of human beings, bringing risks to their well-being and safety. The recent monograph The EU Artificial Intelligence Act: Regulating Subliminal AI Systems, by Rostam J. Neuwirth, addresses this topic in a profound and original way, taking the perspective of Legal Semiotics and the Philosophy of Law. Discussing the concepts of synaesthesia, oxymoron and fuzzy logic, the author proposes a comprehensive, updated and flexible vision of Law, capable of meeting the needs of human beings in the face of these technologies. In particular, Neuwirth makes a convincing case for an understanding of the right to freedom of thought that includes the prohibition of mental manipulation. Brazil has also taken on a pioneering role in regulating new technologies. In this sense, perspectives such as Neuwirth’s could constitute a valuable contribution to the ongoing debate.