Taleb opens Book 4 by discussing the concept of options and their role in antifragility. In essence, options are seen as a vector of antifragility that provide freedom and financial independence, allowing individuals to make decisions based on favorable outcomes, rather than the average outcome. Moreover, Taleb argues that options are a substitute for knowledge and can allow individuals to be “stupid” while still achieving results. Additionally, options benefit from variability and low-cost errors, which means that both volatility and variability yield benefits. Taleb concludes the chapter by emphasizing the role of risk-taking and optionality, which he distinguishes from gambling and lottery tickets, for instance. Even in the Romans’ political system, which at its apex was the epitome of power, relied more on tinkering than on reason, as Taleb points out.

Taleb argues that practical innovations create their theoretical ancestry. He says that the most important discoveries are often simple and obvious, yet difficult to figure out by complicated methods. He emphasizes that often what is most significant can only be revealed through practice, and that every new trial and failure provides valuable information. Taleb also distinguishes between two types of knowledge, one acquired through practice and apprenticeship and the other through academia and scientific knowledge.