Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets that he would make such a statement. To try to at least start to bring this statement into context, I should provide a bit more of the section from where it was drawn:
"Corporations and financial institutions have recently created the strange position of risk manger, someone who is supposed to monitor the institution and verify that it is not too deeply involved in the business of playing Russian roulette. Clearly, having been burned a few times, the incentive is there to have someone take a look at the generator, the roulette that produces the profits and losses...The risk managers' job feels strange: As we said, the generator of reality is not observable." (page 40)
I'll leave you the task of pursuing the full and complete context if you so desire. But Taleb does raise (as he often does) an interesting question regarding the appropriateness and value of a risk manager, as well as what his/her duties should actually be and how they might carry them out.
Can risk be managed?, is essentially the question he is asking. And so, can it? Should it? How to do it? If you agree with Taleb, I'd love to hear from you.
The floor is yours...