What is the author's tone in The Foundations of Buddhism by Rupert Gethin?

Gethin's tone is that of a teacher. He clearly admires the Buddhist tradition, but he
is neither eager nor hesitant to make a case for Buddhist doctrines. Thus, Gethin often defends Buddhist doctrines against common critiques, but he also presents a number of important tensions within Buddhist ideas. Note, Gethin uses plain terms and language in order to allow the reader a clear understanding of Buddhist ideas.