Sagan earned every bit of his reputation as a clear communicator of complex ideas, and that's reflected in this series of essays, originally given as lectures, on the broad theme of our search for meaning through faith and through observation and analysis (i.e., science); the tension between the two, but more often, how they're related and interconnected. Stimulating, thoughtful, and often delightful, and as a series of essays you can put it down and return to it between books, and such.