For anyone interested in reading The Aesthetics of Chaosmos - the Middle Ages of James Joyce, this would be an ideal preparative for a fuller reading experience. In my review of the former, I complained that the ideas Eco posited as medieval could have come from anywhere due to their general nature, but herein such characteristics as allegorism, clarity, formalism and impersonality are elucidated in a way that traces their origins with lots of source references.
Eco is a wonderful scholar in the sense that even at such a young age, he seems to have commanded a downright venerable reading list. His writing is a wonderful mixture of academic precision and controlled artistry, that engrosses yet does not cast doubt on his authority through seemingly unnecessary simplifications. In this book, he is clearly writing about a topic that he is fascinated with, and by doing so he also showcases his patient understanding and, to a slight degree, his visionary aspects.
In Art and Beauty, Eco traces the development of medieval aesthetics (in plural). There was no unified style, but rather there were distinguishable trends of thought that would co-exist with and co-influence the everyday life. We find precious insights of, say, the definition of art and the contemporary attitudes thereof: art was generally seen as something technical and creative, even mechanical, which would include not only crafts but positively menial work. We gain insight into the medieval mindset through references to metaphysics, where beauty is equated with goodness and utility, or mathematical proportions - or where beauty is seen as an actual universal in things as opposed to the eye of the beholder. Interestingly, the subjective side of beauty was emphasised, even before nominalism tore universalism to pieces: this wasn't a case of "horses for courses", it was a case of perspective and how the artistic work would be partly defined by the expectation of angles they would be looked at at the place of exhibition.
What I found to be the most prominent aspects of medieval aesthetics was the use of clearly defined colours, the employment of decorum, the love for allegory (probably not too far off from the adulation of crosswords, though in an artistic form), a strong focus in the formal aspects and the whole of the work and didactic qualities. Of course none of these were watertight, but they would definitely crop up often in the book. The more particular aspects included things like whether God granted artists with divine inspiration, whether the artwork originated in Platonic ideas or as observations of individual objects, whether the Nature was infallible and thus something that should be imitated, or whether she was a wastrel that needs to be improved on, to what an extent could be enjoy the concept of proportion (e.g. was it something that was first discerned externally in an object and then extrapolated as an inner perfection etc.), and also such beauteous things like the metaphysics of light.
That's a mouthful, and so is this book, regardless of its size. It's a packed opusculum that simply radiates contrast to today's views and obviousnesses. These contrasting views provide wonderful armaments for a wholesome appreciation of the works of the medieval period, whether philosophical, theological or artistic (using any definition of the term). I have read quite a bit of medieval writers, and more than often I have been hampered by a somewhat cocky attitude towards the Scholastic neurosis of classification and simplification (which, as an attitude, is probably akin to Cartesian hubris), but reading works like Eco's really shows what futile impatience or damned arrogance that is.
The main thing is to understand and to re-live the experiences of the past - after that, we can choose whether we can assimilate their wisdom or gently decline. Cold intellectualism or abstracted predation of ideas merely impoverish the wealth of experience that the past has, thanks to many precious individuals, passed on to our times.