History of Music Theory

You may be thinking, just as I did when I first gazed upon the obscure title of this infamously-dreaded course, 'history of theory? really? seriously? did people really write about such things in 500 A.D.? did they even know anything about music?'
It is now approximately twenty hours short of five weeks [later] filled with sludging, translations, grimaces, letters written to monks, letter written by monks, shared hysterical laughter, scales that aren't scales, tears, incredulity, ratios, super multiple partients, and thoughts of 'that was cool, now let's forget it'...and after all that, I can tell you, they did know something.

We began with Boethius (480-525), the first notable music scholar whose philosophical heritage--or at least, influence--is documented in stone [er, papyrus] and can be traced to the Latin Middle Ages, and eventually, to present-day Western musical practice. I have to admit, the early philosophical-mathematical musicians weren't completely verrückt...although some of the statements may tempt a modern Joe Schmoe to think so. For example, Isadore of Seville (560-636), claimed that "unless sounds are remembered by man, they perish, for they cannot be written down". Apparently, he never joined his third grade band (sorry, Izzy). On the other hand, Boethius propounded the idea that sound is made not of a single wave, but of many small, recurring, interacting waves that are loudest at the source and fade away in the distance (or "dissolve, as the translator took it). How on earth did he know that?
My favorite quote so far comes from a Boethius contemporary named Cassiodorus (490-583). His treatise, The Fundamentals of Sacred and Secular Learning, is divided into two books; the first is concerned with religious studious, while the second is divided into seven parts, one for each of the seven liberal arts. The section on music contains the quote that has remained with me ever since I first read it (chapter 2, first paragraph):
"The discipline of music is diffused through all the actions of our life...Music is indeed the knowledge of proper measurement. If we live virtuously, we are constantly proved to be under its discipline, but when we commit injustice, we are without music. " [emphasis mine] And thus, we are without proper measurement.