It is an attribute of youth to be passionate and many US Millennials champion causes they find worthwhile. However, they often choose their favorite causes because of their "feel good" characteristics rather than being based on solid arguments. Too often, Millennials are unaware of history and that similar former youths in their days enthusiastically championed equivalent grandiose causes to "save humanity". Often, these ended in disaster, some with millions of deaths.These "causes" are directly derived from the political and economic current issues facing Millennials. It easy to be seduced by the siren's songs of the progressive Left. They are so confident about their science and philosophy and their causes and ideas sound so good and so well thought out that they forget that the most valid law of human behavior is that of unintended consequences, and that the road to hell is always paved with good intentions. The grand causes of the current progressive Left seem foolproof in their logic. Yet, there are significant flaws in their argumentation that this book tries to bring to light. These logical flaws are significant enough to make these whole causes (projects) also end up in disaster as did the ones that preceded them. "Rage or Reason" reviews and analyzes some of the most important current issues confronting Millennials, such as socialism, inequalities, globalism vs. nation-states, climate change and diversity among other things. This analysis uses modern methods such as critical thinking as well as complexity theory and tries to emphasize points that may have been missed or overlooked, or not framed in a proper context. The book also explores the untold ulterior motives of many politicians to promote such causes and how they might get rich from them. It is hoped that this short essay will help the younger generation make a more informed opinion before dedicating themselves to a cause. It is also hoped that it will provide valuable arguments for non-Left individuals when debating with their Leftist counterparts.