In Chapter 9, Bachelard explores more fully the dualities that he references throughout the book. Bachelard rejects the notion that the philosopher should consider these dualities in terms of absolutes. To do so would be to limit them. For example, to consider the terms “outside” and “inside” as absolute terms would mean ignoring the fact that these two spaces often blur into one another. Instead, he promotes examining these dualities through a phenomenological lens to consider what it is to be one of these seemingly opposing forces.

Inhabiting the experiences of these forces allows the daydreamer to understand more clearly the subtleties of being. As Bachelard suggests throughout the book, he sees the dualities of outside and inside as two forces that refine and enhance one another. Both inside and outside can be intimate, and this intimacy is made stronger by the existence of these two forces. Because of these dualities, the intimacy of a room becomes the intimacy of the inhabitant, and the intimacy of vastness in space speaks to the intimacy of vastness within individuals. These dualities in space connect individuals to their own consciousness.

The door functions as an entry into either of these dual worlds. Doors represent temptation and primitive desire.