Man's Greatest Foe: Overthinking, focuses on the multiple aspects that surround overthinking and anxiety. This book will be in chronological order, firstly introducing the reader to overthinking – what it is and why it happens. Secondly, educating the reader on when overthinking becomes concerning and how you can identify between "good overthinking" and "negative overthinking" – make the reader understand that not all overthinking is bad. The book will allow readers to comprehend their situation much better and become aware of how overthinking can negatively impact their lives on every level – physically, emotionally, and mentally. It will also include proven practical methods to help with overthinking and anxiety, allowing the reader to have control of their thoughts and feelings and preventing them from feeling helpless about their overthinking situation. The objective of the book is to give the reader power over their negative emotions and enable them to live a more positive and healthy lifestyle that promotes peace and growth