Firstly it can't be dismissed how prescient a concept the fourth dimension and the importance of time was when this book was penned. The idea would be nothing more than fantasy up until Abbott's final years, when some dude named Einstein wrote a theory. The parts of the book that center around the topic of dimensions and the separations between holds up nearly 1.5 centuries later.

Unfortunately, Abbott goes into great detail on the imagined lives and societies of the creatures in the first and second dimension as a commentary on the Victorian period.