A great paragraph to conclude the preface of The True Believer:
It is perhaps not superfluous to add a word of caution. When we speak of the family likeness of mass movements, we use the word "family" in a taxonomical sense. The tomato and the nightshade are of the same family, the Solanaceae. Though the one is nutritious and the other poisonous, they have many morphological, anatomical and physiological traits in common so that even the non-botanist senses a family likeness. The assumption that mass movements have many traits in common does not imply that all movements are equally beneficent or poisonous. The book passes no judgments, and expresses no preferences. It merely tries to explain; and the explanations - all of them theories - are in the nature of suggestions and arguments even when they are stated in what seems a categorical tone. I can do no better than quote Montaigne: "All I say is by way of discourse, and nothing by way of advice. I should not speak so boldly if it were my due to be believed."
Book: The True Believer
This book was also one of Allen Scarbrough's The 25 best books for a self education and why.