Blow, blow, thou winter wind, Thou art not so unkind As man's ingratitude; Thy tooth is not so keen Because thou art not seen, Although thy breath be rude. Freeze, freeze, thou bitter sky, Thou dost not bite so nigh As benefits forgot; Though thou the waters warp, Thy sting is not so sharp As friend remembered not. Here are images of cold--winter, freeze; of touch--blow, breath; of pain--tooth, bite, sting, sharp; of taste--bitter. How vividly they convey the ache of desolation! Only in words which are imaginative as well as musical are the full resources of verbal expression employed. All the various forms of metaphorical language have the same purpose: by substituting for a more abstract, conceptual mode of expression a more sensuous and imaginative one, to vivify the emotional quality of the situation. When Keats sings, ... on the shore Of the wide world I stand and think Till Love and Fame to nothingness do sink, he has in mind to convey to us that renunciation of merely personal ambitions which comes to us when we "survey all time and all existence." And how does he do it? By evoking the image of the wide stretch of the shore of the sea, which, making us feel our nothingness as we stand and look out upon it, has the same effect, only more poignant. Of the world we have no image--not so, of the shore of the world; and toward what we cannot imagine we cannot easily feel. Oftentimes the metaphor is latent, a mere adjective undeveloped in its implications, as in "bitter" sky; yet the purpose is the same. Incidentally the poet unifies our world for us through his metaphors; not as the scientist does by pointing out causal and class relations, but by exhibiting the emotional affinities of things. He increases the value of single things by giving them the values of other things. Every metaphor should serve this purpose of emotional expression and unification, should be part of an emotional thought; otherwise it is a mere _tour de force_ of cleverness, unrelated to the poetic interest and intrinsically absurd,--the world has no shore and the wind is not bitter; feeling alone can justify such comparisons. Moreover, too many metaphors, or metaphors too elaborately developed, by scattering the attention, or by drawing it away from the meaning of which the image should be a part, have the effect of no image at all. The poetry of Francis Thompson, for example, loses rather than gains vitality through its imaginative exuberance. We object to decadent poets, not because they are sensuous, but because they lack feeling; with them sensation, instead of supporting emotion, supplants it. Such poets seek to atone for their want of vigorous feeling by stimulating our eyes and ears.