" Verticality is ensured by the polarity of cellar and attic, the marks of which are so deep that, in a way, they open up two very different perspectives for a phenomenology of the imagination. Indeed, it is possible, almost without commentary, to oppose the rationality of the roof to the irrationality of the cellar. A roof tells its raison d'etre right away: it gives mankind shelter from the rain and sun he fears. Geographers are constantly reminding us that, in every country, the slope of the roofs is one of the surest indications of the climate. We "understand" the slant of a roof. Even a dreamer dreams rationally; for him, a pointed roof averts rain clouds. Up near the roof all our thoughts are clear. In the attic it is a pleasure to see the bare rafters of the strong framework. Here we participate in the carpenter's solid geometry.
As for the cellar, we shall no doubt find uses for it .. It will be rationalized and its conveniences enumerated. But it is first and foremost the dark entity of the house, the one that partakes of subterranean forces. When we dream there, we are in harmony with the irrationality of the depths. "

― Gaston Bachelard , The Poetics of Space