The opening of the work sets the stage for an examination of the concept of collective insanity, focusing on the life of John Law, a key figure in the Mississippi Scheme. Mackay introduces the reader to Law as both a brilliant financier and a possible conman, illustrating his rise and fall amid the frenzy and greed of the French populace. It describes Law's early life, his gambling exploits, and how he caught the attention of the Duke of Orleans, leading to his ambitious financial schemes intended to restore France's economy after years of corruption. This narrative not only foreshadows Law's eventual downfall but also reflects on the broader themes of ambition and delusion that permeate societal behaviors throughout history. (This is an automatically generated summary.)