Shakespeare evidently believed that his poetry was so great that it would be immortal. He has been right so far. His works are still being read after over four hundred years. In a number of his sonnets he claims he is immortalizing someone he loves by figuratively enbalming him in his poetry. The last two lines of Sonnet 18 are a direct expression of this concept, or poetic conceit:
So long as men can breathe, or eyes can see,
So long lives this, and this gives life to thee.
The word "this" in both cases refers to the sonnet itself. The same thought, notion, conceit, is expressed in the very next sonnet, number 19, which ends with the following couplet:
Yet, do thy worst, old Time: despite thy wrong,
My love shall in my verse ever live young.
Another beautiful sonnet which purports to immortalize a loved one is number 55.
Not marble, nor the gilded monuments
Of princes, shall outlive this powerful rhyme;
But you shall shine more bright in these contents
Than unswept stone, besmear'd with sluttish time.