How does Shakespeare try to make his friend immortal in Sonnet 18?
There are several lines in Shakespeare's Sonnet 18 that refer to his beloved's mortality. However, Shakespeare argues in his concluding couplet that he is making his beloved immortal through his written word. The lines of the concluding couplet are:
So long as men can breathe or eyes can see,
So long lives this and this gives life to thee.
The first word "this" in the phrase "so long lives this" is slightly ambiguous because it immediately follows a description of his beloved's beauty. While beauty alone cannot make a person immortal, the memory of beauty can. But one must ask oneself where this memory would come from. Shakespeare's argument is that because a recollection of her beauty, as well as of her other attributes, has been written down by himself, his beloved will be remembered, which will make her immoral. In that case, the word "this" in his ending couplet refers not to just her beauty, but to Shakespeare's own sonnet. Shakespeare, seeing literature being preserved and passed down throughout generations as art, feels it is safe to assume that the written word is immortal and shall be preserved. Hence, through the very act of writing the poem, he believes he is attempting to make his beloved immortal.
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.