Analysis is a science: there's a right answer out there, and we can all agree when it's found. Troubleshooting is the same way: when the broken bit is found and fixed, the circuit starts working properly.
Design, on the other hand, is an art; there's always more than one way to do it, and the individuality of the designer has a strong influence on the way the design turns out: hence "Art, Science, and Personalities".
This isn't to say that a good designer does unusual things without a good reason, or adds expensive bells and whistles because he happens to like them. What it means is that for designs that are not routine, the designer's personality has a lot to do with how it comes out.
To become an expert designer, you need a well-developed technical taste. Once you have a design that works at some level, it's that sour feeling in the back of your mouth that will tell you that it isn't right yet, that it can be simpler, cheaper, or more reliable. There aren't a lot of other sources of that information.
Arts are taught by apprenticeship. But where are you going to go to get taught this stuff nowadays? EE departments are going more and more to software, as shown by the vast number of graduate EEs who don't know which end of a soldering iron to hold. Jim Williams can't be everybody's mentor, but in this informal (and sometimes whimsical) book, he and his friends show us how the best analogue designers in the business go about things. You know what? One of the most important elements in the art of design is *play*.
Maybe listening in on these guys playing at being analogue designers isn't quite the same as sitting elbow-to-elbow with them, but it's as close as most of us are going to get, and it's terrifically valuable. I recommend this book to anyone who wants to become a better analogue designer, and who is not easily put off by whimsy in technical writing. (I find it refreshing and fun, myself.) I've owned this book for 6 or 7 years, and it's about ready to fall apart from rereading.