To define the poem as the artist’s experience is a better solution. But it will not do as it stands since nobody but the artist has that experience. We must be more ingenious. We cannot take any single experience as the poem; we must have a class of more or less similar experiences instead. Let us mean by _Westminster Bridge_ not the actual experience which led Wordsworth on a certain morning about a century ago to write what he did, but the class composed of all actual experiences, occasioned by the words, which do not differ within certain limits from that experience. Then anyone who has had one of the experiences comprised in the class can be said to have read the poem. The permissible ranges of variation in the class need (of course) very careful scrutiny. To work them out fully and draw up a neat formal definition of a poem would be an amusing and useful occupation for any literary logician with a knowledge of psychology. The experiences must evidently include the reading of the words with fairly close correspondence in rhythm and tune. Pitch difference would not matter, provided that pitch relations were preserved. Imagery might be allowed to vary indefinitely in its sensory aspect but would be narrowly restricted otherwise. If the reader will run over the diagram of a poetic experience given in Chapter XVI and consider in what respects his and his friends’ experiences must agree if they are to be able to refer to them indifferently as though they were one and the same without confusion or misunderstanding, he will see what kind of thing a detailed definition of a poem would be. This, although it may seem odd and complicated, is by far the most convenient, in fact it is the only workable way of defining a poem; namely, as a class of experiences which do not differ in any character more than a certain amount, varying for each character, from a standard experience. We may take as this standard experience the relevant experience of the poet when contemplating the completed composition[75]. Anyone whose experience approximates in this degree to the standard experience will be able to judge the poem and his remarks about it will be about some experience which is included in the class. Thus we have what we want, a sense, namely, in which a critic can be said to have not read the poem or to have misread it. In this sense unrecognised failures are extremely common.