Because maybe the best way IS up.
The Pantheon in Rome and the Hagia Sophia are examples of the investment of time and money and cleverness that people will put into building tall religious buildings. The problem was that the insides, although lofty, tended to be dark because windows weakened the structure, especially if they were near the bottom of the building.
Some time in the early 1100’s a clever person armed only with a pair of compasses and a set-square invented the gothic (or pointed) arch, and the flying buttress (which is a support beam sitting on half an arch). The English seem to be a bit embarrassed by flying buttresses and often hide them within the fabric of the building but the French simply loved them and their cathedrals just went up and up and up. Inside they look beautiful, from the outside they have a certain Shelob-style crouching spider look according to Doris, although flying buttress-lovers will certainly disagree as their eyes trace how the downward pressure of roofs and walls is elegantly passed to thicker support elements further away from the main building.
Bourges Cathedral manages to pull this act off.
Approaching from the town end, you come to the west end which has everything you have come to expect from French Cathedrals, with towers and big big door portals that say THIS WAY IN!!! while encouraging you to linger and look at the sculpture. More about that later as Doris and Sid scamper eagerly into the cathedral… to be hit with exactly the shock and awe effect that the creators had in mind.
Even Sid is silenced, and it takes him a while to recover enough to read out the information board saying that the nave is 117 m long, 41m wide and 37m tall and with five levels – three window levels separated by two gallery levels. Mr Wikipedia has an extensive and well-illustrated article which explains just why there is so much light coming in, which may keep our single but dedicated reader happily occupied for several minutes while Doris wanders round and admires the extraordinary mediaeval stained glass.
The cathedral was apparently complete enough by 1225 to be able to “host a large council condemning the heresy of Catharism”. See also blog post called Nous N’Aimons Pas Les Gens De Mison. Sigh.
Dazed with wonder, Sid and Doris go back out under the portal illustrating very clearly the awful fate that awaits all Cathars, and you too if you don’t pay the church a lot of money regularly. Note particularly the frogs, also the smug angels.
PS here is the outside view from the east end showing the effort being provided by the flying buttresses to keep everything upright.