Anthropometry concerns the measuring of human beings. Throughout its history, it has been associated with both scientific and pseudoscientific methods. Within The Mona Lisa Vanishes, investigator Bertillon uses anthropometry as a method for identifying criminals by their unique measurements. Nicholas Day differentiates Bertillon’s application of the data from others who interpreted it to justify their own racist assumptions.

A conspiracy theory differs from a conspiracy in two ways. First, a conspiracy theory is when one attributes an event to a conspiracy by powerful groups with ominous intentions, especially when a simpler explanation is evident. Second, a conspiracy theory often exists in opposition to mainstream or expert views. Conspiracy theories tend to be associated with emotional and prejudicial beliefs, with believers imagining the reality they fear.

Cubism was an avant-garde artistic movement pioneered by Spanish painter Pablo Picasso, among others, beginning in 1907. As in the Renaissance, cubism was concerned with perspective, analyzing objects and people but for a radically different end. Rather than represent what things looked like in nature, cubism sought to represent the nature of reality by drawing attention to the artifice of a painted work. As Day suggests in the book, cubism was a response to the rapidly- changing modern world of multiple perspectives and cultures.