In a world where more and more fake news is being spread, it is becoming increasingly difficult to distinguish truth from lies and knowledge from opinion. Disinformation campaigns are not only perceived as a political problem, but the fake news debate is also about fundamental philosophical questions: What is truth? How can we recognize it? Is there such a thing as objective facts or is everything socially constructed? This book explains how echo chambers and alternative worldviews emerge, blames post-factual thinking for the current truth crisis, and shows how we can escape the threat of truth relativism. The contents: - Fake news - Post-truth epistemology - Theories of truth - Information and knowledge The target groups: - Philosophers - Media scientists - Political scientists - Social scientists. The author: Thomas Zoglauer (Dr. phil. habil.) teaches philosophy at the Brandenburg University of Technology at Cottbus-Senftenberg and at the Graduate Academy of the University of Stuttgart and is the author of numerous books on the philosophy of technology and applied ethics. This book is a translation of an original German edition. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation.