In "The Crime of The Communist" by G. K. Chesterton, the author was describing three men and the surrounding architecture of Mandeville College, saying:
They themselves, in a curious quiet way, were quite harmonious with their surroundings. Though the Tudor arches that ran like a cloister round the College gardens had been built four hundred years ago, at that moment when the Gothic fell from heaven and bowed, or almost crouched, over the cosier chambers of Humanism and the Revival of Learning — though they themselves were in modern clothes (that is in clothes whose ugliness would have amazed any of the four centuries) yet something in the spirit of the place made them all at one. The gardens had been tended so carefully as to achieve the final triumph of looking careless; the very flowers seemed beautiful by accident, like elegant weeds; and the modern costumes had at least any picturesqueness that can be produced by being untidy.
I found that Gothic means "Gothic architecture", which is well-known for its arches and bowed patterns, and that Revival of Learning refers to the Renaissance, and that cosy means relaxed, but I can't get the whole meaning of this sentence.