I came across with this book accidentally, i rarely found it in bibliographies, but it was an excellent surprise. The aim of the book is to show that differences between the concept of arahant, bodhisattva and mahasiddha are more virtual than real. Full of citations from Sutta Nikaya and most important texts from Mahayana and Tibetan traditions will help the reader to really understand some of the most important topics about the difference of the three vehicles. One of the most interesting part was the the understanding and the "skillful" use of language in Buddhism religion, with an interesting confrontation between Pali Buddhism, Nagarjuna and Wittgenstein. Highly recommended.