Allusion is the most striking of the ways in which poetry takes into its service elements and forms of experience which are not inevitable to life but need to be specially acquired. And the difficulty which it raises is merely a special instance of a general communicative difficulty which will probably increase for the poetry of the future. All the thought and feeling of recent man goes on in terms of experience which is much more likely to be special and peculiar to the individual, than, let us say, the experience of medieval man. The survival of medieval man on such a vast scale among us should not mislead in this matter. The people who are most keenly and variously interested, that is to say, the people whose lives are most valuable on our theory of value, the people for whom the poet writes and by his appeal to whom he is judged, inevitably build up their minds with far more varied elements than has ever been the case before. And the poet, in so far as he is equal to his opportunities, does the same. It is hard, and, in fact, impossible, to deny him his natural and necessary resources on the ground that a majority of his readers will not understand. This is not his fault but the fault of the social structure. Given present conditions and future developments in the directions indicated by the changes of the last two hundred years, it is extremely probable that poets will become not less but more allusive, that their work will depend more and more not only upon other poetry but upon all manner of special fields of familiarity.[73] Many of the finest and most widely significant experiences, and those therefore most suitable for poetry, come nowadays, for example, through reading pieces of advanced research. There is nothing new in this, of course, nothing that was not happening when Donne wrote. The difficulty springs from the fact that research is so much further ahead than it used to be. [71] Cf. _Prometheus Unbound_, Act 1: ‘the air around them looks radiant as the air around a star’; also _Triumph of Life_: ‘as veil by veil the silent splendour drops From Lucifer’. [72] _Paradise Lost_, Bk. II, line 672. [73] A very interesting contemporary example in connection with which the problem arises perhaps more acutely than ever before is Mr Eliot’s _The Waste Land_ already mentioned. The impatience of so many critics and the fact that they have complained of the presence and necessity of notes well illustrates the confusion which prevails upon this question. A more reasonable complaint would have been that Mr Eliot did not provide a larger apparatus of elucidation. (See Appendix). CHAPTER XXIX Permanence as a Criterion Wherewith being crown’d, Crooked eclipses ’gainst his glory fight. Shakespeare, _Sonnet LX_.