An essay on the theory of literary criticism that eschews theoretical commitments of its own - its ground or ‘foundation’ if you will - must be taking an unsuitable form of risk. But I hope that the further implications of the case studies that follow will justify the exploration. They describe the strange and pervasive power of critical practice: theoretical standpoints are necessarily evoked yet the grandest theoretical design becomes oddly evanescent and particular theories disintegrate in the circumstances of their use. Hence the myth of theory is also its life; its value lies not in what it claims but in what it does, and what it does is not what it is thought to do. We shall find that theory seldom operates as it would intend. But it creates at the cost of a necessary fiction that transforming energy which saves us from the entropy of established practice. Its evocation transcends its function, its myth, its literal claims. The rhetoric of criticism employs and transmutes - yet its structures fail the test of generalizability. It was as an illustration of this point that I had thought to title this book ‘worms dying in flower’. But the allusion and its analogy might have been obscure to some, and have led to misunderstanding on the part of others. So I have contented myself with printing the appropriate lines.