Pierce traces the development of themes and story structure in sf from utopian proto-sf, through so-called 'gothic sf' like Frankenstein; Or, The Modern Prometheus, concerned with sin and punishment, on to space opera and future history. Though anglo-centric, it includes some information about French, German, and Russian sf.

In the early pages, when treating utopian fiction, Pierce did not give enough detail, and at the end, the multiple pages devoted to e.g. Asimov's Foundation series or Niven's Known Space series were excessive. The middle of the book was a happy medium.

The book is probably best viewed as an annotated bibliography of certain themes; its analysis, of necessity for a book with such a broad scope, is too shallow to make it of much use outside that.