"We are all, each in our own way, seekers of the truth and we each long for an answer to why we are here. As we collectively scale the mountain of explanation, each generation stands firmly on the shoulders of the previous, bravely reaching for the peak."

An enthusiastically optimistic quotation to take us to the end of the book, Greene shares with the reader some of the excitement arising from this new breakthrough in theoretical physics (string theory), and seeks to justify the motivation for him and for all scientists to conduct research. The human mind functions properly only when there is a goal in sight, and when there is support beneath. The greatest weapon mankind harbors against the absurd, the unknown is self-persuasion, the ability to narrow the concentration and to grasp at whatever elegant, logical hope it can find in this universe.

"What are we to make of this? Does it mean that on a microscopic level the universe operates in ways so obscure and unfamiliar that the human mind, evolved over eons to cope with the phenomena on familiar everyday scales, is unable to fully grasp "what really goes on"? (...) No one knows."

Greene is taking about quantum mechanics, a theory that simply 'worked' to confirm experimental testing, but had no elegance, no logic. This quote isolates the very paradox of objective truth and understanding. While science is the keeper of 'objective truths', they are simply 'tricks' that help predict or regulate reality. It is akin to (and this is my analogy) a definition: if every new word encountered within a definition for some unknown word is to be looked up, then it is simply logically impossible to 'understand' the 'essence' of a word - to know it. And yet humans do communicate. Thus, the problem is with representation: once the subjectively perceived object is represented by an objective symbol (a word), absolute understanding is lost.

"Calling it a cover-up would be far too dramatic. But for more than half a century- even in the midst of some of the greatest schientific achievements in history - physicists have been quietly aware of a dark cloud looming on a distant horizon."

The problem was the incompatibility of quantum mechanics (explaining the very small) and General Relativity (explaining the very large). This energetic start to the book gives the reader an idea of how awkward, almost embarrassing it must have been for scientists to advance both frameworks of thought with the fear that all one's work will we futile: that neither theory will ever explain all of the universe. This sets the context for the introduction of string theory, which did unify the two former theories.

"Non-scientists sometimes blur the distinction between the intimidating language- mathematics- in which physics is developed and the engrossing ideas with which it tussles. But that would be like my trying to asess Huckleberry Finn by reading it in Greek. While I use the Greek alphabet all the time, I don't speak a word of the language..."

Here Greene, still in the Preface, stresses the conceptual nature of physics, and the requirement that the ideas be understood logically through words as well as calculated with mathematics. Therein lies the bilingualism of physics.

"Be it a young student trying to decide on a direction of study, a working professional seeking something beyond the daily grind, or a retiree who'd finally found the time to read up on developments in science, if I could help guide them...the task of writing The Elegant Universe would have been worth the effort."

This quotation is taken from the preface to the Second Edition, and enlightens on the task Brian Greene intended his book to serve in our society - that is, informative, but not intrusively so.