Form is one of the more slippery concepts in literary criticism: elusive of definition, unavoidable in practice. Even the most doctrinaire of political critics, questioned as to why they are writing about novels to expose economic injustice, rather than about the more obvious evidence of income distribution, must justify their choice, in the end, by claiming there is something distinct about the novel as a form that offers insights unavailable elsewhere. That distinction has often been a dubious one. In a claim that set the tone for attitudes towards form at the beginning of the period covered by this Companion, Fredric Jameson argued that form named a special kind of deception: ‘the production of aesthetic or narrative form is to be seen as an ideological act in its own right, with the function of inventing imaginary or formal “solutions” to unresolvable social contradictions’. This inverted the tradition, beginning with Kant and Schiller, of using form to name what distinguished literature in a positive sense from other uses of language. This use of form was dubious in its own way, acquiring so many contradictory meanings that it became, as Angela Leighton observes, ‘a noun lying in wait of its object’. Yet whether the target of censure or praise, literary critics have never strayed far from using form to talk about the relationship between what Raymond Williams identified as two persistent but different meanings: a ‘visible and outward shape’ and an ‘essential shaping principle’. The attempt to talk about both at once is what makes the concept of fictional form so slippery. In trying to analyse as tangible that which can only be virtual, form must always evade our grasp. You can’t point to linear causality, just as you can’t touch first-person narration, but these are the shapes and shaping principles we use form to name. Form is an attempt to talk about what enables language to mean by imagining something tangible and material lying between words and their referents, be they themselves real or imaginary.