It's a highly informative and non-judgemental history of not only celibacy, but also sexuality in general throughout many different times and cultures. I loved the way Abbott managed to relate each form of celibacy to the social, religious, moral and economical circumstances in which it appeared - it gives the reader a broader understanding of societies and individuals who embraced or rejected celibacy.
In addition to this, History of Celibacy is beautifully written, maybe more difficult but extremely pleasurable to read. (It's also good for learning new words, especially if you're a non-native english speaker. I wish I'd read this book before I took my GRE, it would've added at least 50 points to my verbal score)