No literary genre promotes its utility as explicitly as the "how-to" book. Although instructional manuals written for a wide range of specialized groups existed prior to the advent of print, the unprecedented forms of reproduction and dissemination that print enabled effectively transformed the how-to book into a new genre, one defined by its potential availability to both specialized and non-specialized readers. As an instructional guide adaptable to all spheres of public life, the how-to book taught skills integral to fields like theology, medicine, the mechanical arts and domestic husbandry, even as it also guided readers in rhetorical practice, in social, ethical and professional forms of conduct, and in the cultivation of personhood itself.
Such books are, on the one hand, clearly didactic, grounding their authority in the expertise of the author. On the other hand, these books also enabled the reader to inhabit new forms of authority (it is no coincidence that self-help books are so often in the vernacular). In fact, by positioning readers as actors, by requiring them to actualize knowledge by performing it, these books not only enabled the appropriation of authority, but also promised a transformation of identity. Rather than being at the margin of the genre, therefore, the conduct book and psychological self-help book were arguably at its center, since they made so explicit the idea of self-making or transformation that underwrote even the more narrowly instrumental how-to books.
It is important to remember that how-to books were oriented toward fields of knowledge still in formation. As such, they often required readers to think more imaginatively and speculatively than a phrase like "didactic literature" suggests. At the same time as they fitted their readers into this or that prescribed identity, early how-to books offered them a glimpse beyond the horizon of prescriptive knowledge, insisting as they did on the reader's participation, and on the logical priority of his or her experience. The how-to book gives experience form. In this sense, Baconian empiricism (which so disrupted the grounds of earlier scientific authority) can be seen as the genre's logical extension, yoking together as it does experience and experiment, transforming the practice of the one into the method of the other.