What is the author's tone in Brecht on Theatre: The Development of an Aesthetic by Bertolt Brecht?

Because the book is a manifesto of sorts (a call to arms, an exhortation to awaken), there are several aspects to its tone that might be summarized by the term assertive. There are times when it becomes lecture-y, at times reflective, at times celebratory, at times condemnatory - but at no point, in any of the writings, does it become anything other than instructional, and often self-righteously so. In other words, the book is written from an entirely subjective tone that tries to present itself as objective but ultimately fails - the book, and presumably its writer, wants too much to convince the reader of the correctness of its socio-political perspective. There are three ways in which this tonal quality can/is likely to affect the reader, both depending upon the nature and/or identity of that reader.