Boy is this a hard book. In the Middle Ages scholars everywhere in Europe wrote in Latin. This meant they could be understood everywhere, but not by everybody. There is a lingering effect of this in that academic language relies heavily on words of Latin origin. This makes it difficult to read if you are not used to it. It does have a good reason for this of course – everyday language varies across the English speaking world and words have associations that can cloud their use and their meanings are continually changing. So you can see why that is how scientific papers are written. But it is still heavy going to plough through a whole bookful of it.