One of the chief difficulties of writing a book about mathematical genius is that the average person views mathematics as calculation or opaque. (Aside: calculation has lost its luster since the advent of the pocket calculator.) After a certain point, in Decoded there is no longer any detail about mathematics. The reason is probably that it is classified, but also that the writer could not probably do it justice or if he tried he would just confuse his audience, although some of us would like to understand the cryptography referenced. Maybe his approach here is the reproduction of a conversational technique that people dealing with difficult matters adopt: he is reporting only what his interviewees can report to him, a non-expert.
A lot of wild cardinal rules are made about cryptography that seem ridiculous on the face. For example, that a person is either a decoder or encoder. Or that once a person makes a cipher he is used up as a cipher is characteristic and must be unique. All of this is fascinating. The idea behind this might be that the nature of a task, not merely the native abilities of the practitioner, is what determines the result. Once one door is open another is shut.
Perhaps, making statements of impossibility is mostly a literary device in order to make the character of Rong Jinzhen, a practitioner of two worlds, unbelievable or one-of-a-kind.
There are many such allegories in the book and other devices used to indicate his genius. Here is his evolution of problem solving at different stages of life:
- Spelunking into a cave without proper light
- Performing tasks in darkness
- Constructing a dark room yet not finding ones way out
Danger, traps. But due to his daring, he is recognized as a genius.