This is hard stuff. Of course the writing is difficult. It's a major philosopher trying to deal with just about the most difficult of all philosophical problems; but in language which is about as clear as anyone could manage. Might the last reviewer simply have been out of his depth?
Hard slog of a topic which is covered by this book in a difficult style. Too many long sentences used such that you forget the reasoning half way through. Then you have to go over it again. There must be a better way.