This is full of highly entertaining anecdotes, pithy quotations and useful snippets of knowledge which add up to a cogent argument only by making some outrageously sweeping assumptions.
It is difficult to argue with the excellent summary of risk management during the course of this century, and anyone looking for a thought-provoking introduction to Markowitz and all that need look no further.
However, to get there you need to get past a broad swipe at the History of Ideas which attempts to show you how clever we are compared to the ancients. The author's basic premise is that in The Olden Days when we were unable to accurately measure risk, people cheerfully put their faith in the lap of the gods, blindly setting to sea during storms, building their houses next to flood-prone rivers, all the while serenely unaware of how the odds stacked up against them. Then, as we became increasingly aware of the beauty of zeroes, Arabic numerals and standard deviation, we were increasingly able to measure what was going on and therefore control it. Well, that assumes that you cannot control risk without first being able to accurately measure it. I just don't believe that the Greeks never spotted that their unevenly-shaped dice fell more often on one side than the other - kids in playgrounds spot that kind of thing easily. I also rubbed my eyes in disbelief at the idea that the period of Columbus was the first time in history that wealth was created by mutually beneficial trade, rather than by conquest and pillage - is this a commonly held belief? And while we're being pedantic, Pascal's Pensées are not his "autobiography", nor is it safe to make assumptions that the fragments in them are all expressions of his own beliefs.
Nevertheless, an enjoyable read that is satisfyingly thought-provoking.