and one last point , which those will feel who to-day preserve the ancient pietas towards the past : beowulf is not a 'primitive ' poem ; it is a late one , using the materials ( then still plentiful ) preserved from a day already changing and passing , a time that has now for ever vanished , swallowed in oblivion ; using them for a new purpose , with a wider sweep of imagination , if with a less bitter and concentrated force .