Beethoven helped to further unify the different movements in multi-movement works with the invention of the 'germ motive'. The germ motive, or 'germinal motif', as it is sometimes called, is a motive that is used to create motives and themes throughout a whole work, without making it obvious that such a thing is being done. Thus, all the themes in a piece can be tied back to a single motive in the work. An early and famous example of this is his sonata 'Pathetique', where all of the subjects used in the first movement originate from a germinal idea derived from its opening bar. Similarly, the opening bars of his Eighth Symphony is used to derive motives to be used throughout the whole symphony. This device lends unity to a work or even a group of works (as some motives Beethoven used not only in one work but in many works) without repeating material exactly or turning to canonic devices.