What prevented Schubert from completing his eighth symphony?

Answer 1

There are a few possible answers; 1. Schubert had other more lucrative offers (such as an Opera commission) available to him and decided to pause work on the Eighth until a later date. 2. He realised that there was little chance of the work being performed, so decided to abandon it's composition. 3. The final movements were used elsewhere in Schuberts work. For example, the final movement may have been used as an extensive Entr'acte in the opera Rosamunde. 4. Schubert was in fact satisfied with the Symphony in its two movement format, and felt that those movements were so strong that anything that followed would prove anti-climactic. 5. Some of the later great works of Beethoven, a god to Schubert, contained only two movements, most notably his last piano sonata op. 111. Schubert may not have considered a two-movement work to be 'unfinished' at all. Which is the correct answer? Who knows...