I appear to be in a minority here, in not believing the book to be a work of genius and a grand look at important philosophical ideas.
The book is similar in some aspects to the later, and I believe better, Childhood's End in that the plot is about the transfiguration of human society. In Childhood's End a great transfiguration into another level of existence and in this one the waking up of two moribund earth societies in the far future.
Slow and ponderously we move through the book, exploring the earth and the universe. We find the universe empty, almost completely devoid of the galactic empire that permeates the legends of earth society. Though there is a point, and it is realized at the end of the book spending 212 pages exploring empty vistas is not my idea of entertainment.
At the end, mankind has awoken and again given an opportunity to grow and become more than the fearful earthbound race it had turned into. We end with much work to do and the idea that it is the journey that is worthwhile, not the destination.
This golden age classic sadly is showing it's age. The ideas now co-opted and familiar to everyone and the plodding plot barely able to hold a reader's interest. The final payoff just barely makes it a worthwhile read, and there is some historical significance of this early example of the conceit of examining deep philosphical issues.