Flatland.

I just finished the book "Flatland"; written in 1884 by Edwin A. Abbott. The narrator - himself a square - lives in a two-dimensional world called Flatland. His wife, like all women in Flatland, is a line. The more sides one has the higher one is in the hierarchy. Indeed, the circle is the highest class. In an amazing way the book not only guides one through the implications of life in two dimensions, it introduces the reader to perceiving dimensions.

The narrator, for example, visits Lineland (a one-dimensional word) and while he is a square he is perceived solely as a point because people in a one-dimensional world like Lineland only have north/ south; this in contrast to north/south, and left/right in Flatland, and in contrast to north/south, left/right, and up/down in Spaceland.

Similarly when a sphere from Spaceland (a three-dimensional world) visits Flatland he is perceived as a circle. Indeed, what people from Flatline understand is solely a single plane cutting through the sphere:

People in Flatland (Lineland) just can't perceive the idea of there being more than two dimensions (one dimension). Is there a fourth dimension out there that we as people living in Spaceland just can't perceive?