If we return to the late Middle Age centuries, we will see that even then the architect makes use of a discourse, but insufficiently coagulated, because he has faith and canon. The theory is implicit, is minimal and is included in the canon. There are many experiments, but the intention of the author seemed to be that of writing a handbook for his apprentices. However, what we found there are notes and sketches with very concise explanative legends which make the book almost useless in the absence of an oral commentary. It seems to be rather a collection of recipes for their working conditions.
Art seems to consist in isolated observations waiting for a unifying theory.
But the absence of an unifying theory does not weaken the unitary character of the works, which is encountered only in epochs of deep convictions, like that after year 1000. Today, however, theory plays the main role, it is taken as inspiration source and legitimization. In exchange, experiments develop in peripheral zones. This comes, among others, from the fact that in architecture experiment is much more expensive that in the other arts. On the other hand, he is no more closed in the canon but he looks for the opening towards new fields.