One of the reasons I continue to be interested in the "time-line" of the final movement of Ludwig van Beethoven's E major (Opus 109) piano sonata is because, at a subjective level, it gives the impression of an journey through an extended duration of time. Because the tempo is a slow one (Andante molto cantabile ed espressivo in Opus 109), I have been particularly concerned with how both performer and listener can orient themselves throughout that duration. Furthermore, this movement is far from an isolated case. On my CD of performances by Egon Petri, the second movement of Beethoven's final piano sonata (Opus 111) is even longer by about four minutes; and this is a relatively familiar time scale in late Beethoven. Even before Opus 109, we have the Adagio sostenuto movement of Opus 106 ("Hammerklavier"). This is also the scale of the first three movements of the D minor (Opus 125) symphony ("Ode an die Freude"), whose Adagio molto e cantabile movement takes a more prolonged approach to the same double-variation form that Beethoven had introduced in his C minor (Opus 67) symphony and later pursued in his Opus 97 ("Archduke") piano trio. Then there are the late quartets (which were such an inspiration to Thomas Stearns Eliot), particularly the Heiliger Dankgesang eines Genesenen an die Gottheit, in der lydischen Tonart movement of Opus 132, whose temporal scale is practically that of an entire composition, rather than a single movement. On the other hand, in the string quartet canon, Beethoven is already beginning to approach this scale in the Molto adagio movement of the second of his Opus 59 ("Razumovsky") quartets.
One possibility is that Beethoven was seeking a rhetorical alternative to the "significant silence" technique he had engaged in so many of his earlier works. As I have previously observed, he could be both witty and serious in his use of silence; but, when he was being serious, the silence could serve almost as his effort to make time stand still. Perhaps, then, at some point in his personal development (possibly as a reaction against the suspension of time anticipated in the first part of Johann Wolfgang Goethe's Faust, possibly in recognition of the limitations of his own body in his "Heiligenstadt moment"), he recognized that, by its very nature, time cannot come to a halt; and trying to invoke the cessation of time would be a futile pursuit. So he rechanneled his creator spiritus to explore the prolongation of time, rather than its suspension; and turned to different forms of adagio movements to provide the field for such exploration. He probably did not realize that this exploration would launch a "temporal arrow" through the nineteenth century, as subsequent composers would seek to sustain listener's attention over longer and longer periods of time (which Donald Francis Tovey saw as the "deep structure" of music history, at least when he was writing the entry on "Music" for the eleventh edition of the Encyclopaedia Britannica). I suspect that all that really mattered to Beethoven was that he realized (whatever Goethe may have suggested) that he would never encounter a moment of such satisfaction that he would wish time to cease over it; and, instead, he became an "eternal explorer." The nineteenth century clearly gained much from his explorations; and we can continue to gain from them today, even in more mundane areas such as the underlying behavioral nature of our own listening practices.