Dreams can have many effects on people, both good and bad. At their worst they can cause people to waste their lives (and the lives of others) chasing a fantasy to no good end. However, when tempered by the knowledge of science and the power of engineering dreams (and people) can be at their best. They can produce wonderful results such as telescopes that let us see and study the universe, rockets that let us break the boundaries of earth and reach out to it, and perhaps some day an elevator that can ascend to space and make those rockets obsolete. The latter is the subject of Clarke's book.
There is more to it than that, however. The story takes place in a fictional land that greatly resembles Sri Lanka, and it is a land that the author clearly loves. Clarke had been living in Sri Lanka for roughly 20 years at the time of writing this book and it obviously affected him. Much effort is taken to depict the scenery and the culture of the place--unusual for Clarke--and he even digs into some (pseudo) history at the beginning of the book spending a few alternating chapters describing the fall of an ancient king and the surviving architecture resulting from his rule, as well as describing the lasting Buddhist influence on the land, and describing their beliefs rather gently for the most part. He did have a well-known soft spot for Buddhism.
His fondness for Buddhism did not extend to theistic religions, however. Throughout the first half of the book there are short chapters interspersed with the main story telling a tale of mankind's contact with a robotic satellite sent out by an alien race that is capable of learning some of Earth's languages and communicating back and forth as long as it can process the conversation in terms of logic (rather than emotion). Various documents are uploaded to the satellite so it can read them, including Aquinas' Summa Theologica--in which it finds and details 149 fallacies, all of which are found to be accurate--and other arguments in favor of the existence of God which it dismisses using the information about Occam's Razor that was uploaded into it. In the process the satellite severely damages belief in (theistic) religion on Earth and helps bring it to a quicker end. (It is taken as a given that the end of theistic religion was inevitable anyway.) I'm a critic of religion myself, but all of this seems a bit too convenient, to the point of being silly; more importantly, it does not mesh well with the story. These interludes appear randomly throughout the first half of the book and then disappear in the second half until they are finally tied into the main story at the end, which results in a very jarring effect. Until you hit the end of the book those chapters feel like nothing more than a vehicle for Clarke's preaching and can be irritating. This is unfortunate as it is the book's only major flaw and could have been fixed if Clarke had been willing to put more time into fleshing out these sections and integrating them into the story--or if his editor had been willing to reign him in and remove that material. I should also note that the characters he presents are not masterful, well-drawn specimens of character writing that will influence future generations of writers, but that didn't bother me as much because they are not the focus of the story and didn't get in the way.
The space elevator and the journey to building it--all the way from fighting for funding to hammering out the flaws in the engineering--is the meat of this story and that subject is handled beautifully. Clarke's passion for a the subject comes through, as does his belief in reason and what men and women can do when they dare to temper their dreams with the power of science and the willingness to use their minds rather than ignore them in favor of their hearts. Throughout the story one will find setbacks and progress, tension and release, fear and joy in equal measures. The strongest commendation I can give this book is that the author manages to bring out that sense of wonder at science, the universe, and mankind's (potential) accomplishments that science fiction is so well known for in theory but so often fails to achieve in practice. This is a very difficult task that is rarely accomplished, and that leaves this book as one to be treasured in spite of its flaws. Read it.