In our era, well-known ideologies are being questioned from many sides and for many reasons. Many countries are in a process of transitioning to new forms of societal organization. Other countries are struggling to establish democratic institutions, while in others democratic institutions are misinterpreted as arbitrariness and lawlessness, and in others they are being dismantled brutally and violently. In Greece, democratic institutions seem to have relatively solid foundations, but at the same time, worrying tendencies of lawlessness, arbitrariness, and corruption are observed. Simultaneously, the stagnation of the economy during a long period has created serious problems of unemployment, unequal distribution, and social injustice. In the midst of this confusion, the ordinary person needs a simple and understandable way to comprehend what is happening around them and at the same time be able to evaluate it. This book has exactly this ambition, namely to present in a simple and understandable (but not simplistic) manner basic concepts, ideas, and theories with which the reader can comprehend the important issues of our era and evaluate them.