An overview/ primer of the major sicentific/philosophical/religious arguments for why there is something rather than nothing, i.e. the book's title. Holt does a commendable job at summarizing the major point of each theory and engaging in debate with many of the proponents of these theories.
In the end, there is no answer to the question of why does the world exist, why is there something rather than nothing. No answer that stands up to logic and rationale. In the end the book's unstated premise reminds of lyrics by Neil Peart:
"The point of a Journey
is not to arrive."
Restated for this work- the point of a question is not its answer but the seeking for an answer. The point of existence is not how it came into being but existing itself.