According to Beethoven
Everything that is called life should be sacrificed to the sublime and be a sanctuary of art.
According to Maynard Solomon, in Late Beethoven: music, thought, imagination (2003),
In the wake of personal disappointments and as the consciousness of his own mortality cast a lengthening shadow, Beethoven was acutely aware that he would not have sufficient time to complete his creative endeavors.
Thus, Beethoven had to decide how he was to spend his remaining time on earth, whether to try to fill the dwindling days with simple pleasures or to pursue his dedication to great artistic challenges, or even to raise the stakes in his creative exertions. Predictably, but not without scorching conflicts, he opted for art against life, and this answer is written large and repeatedly throughout his Tagebuch […]
Beethoven’s choices were designed to enhance his creativity and to provide favorable conditions within which it could flourish. He set in motion a process of stripping down to essentials, eliminating whatever he perceived to be superfluous and trivial, even renouncing the possibility of love and marriage and setting limits on his affectionate and social interactions. Knowing that the time remaining to him was sufficient for the working out of only a relative handful of his ideas, he steeled himself for the task ahead […]
Contemplating the encroachments of time and mortality, Beethoven set his priorities, determined which compositions he would write, and eventually laid out an ambitious program. By 1817-18 at the latest, when he was writing the closing entries of his Tagebuch, he had settled on a series of compositions, works that constituted the components of a vast creative effort. (Indeed, with the exception of the late quartets, the great works of the last decade were all actually begun in 1817-18.)