In this poem William Shakespeare has introduced the theme of time in two dimensions: 1. Time as destructive force 2. Internal quality of art which transcends the ravages of time .
Comparison of the poets friends beauty :
In Sonnet 18, in the very first line Shakespeare has compared the beauty of his dear friend with that of the beauty of the summer’s day.
Supremacy of the poets friend’s beauty :
The beauty of the poet’s friend is more adorable than the beauty of the summer’s day.
“Thou art more lovely and more temperate”
Eternal, Ideal and Unchangeable beauty :
The poet says that beauty of the summer’s day is subject to fluctuations. But the beauty of the poet’s friend is eternal and unchangeable against time.
Beauty beyond age and death :
The poet affirms that beauty of his friend is more beautiful than the changing beauty of the nature. It is beauty of the sort whose beauty cannot be entrapped by age or death.
Everlasting quality of Art / Triumph of Verse over Time :
This poem establishes the Triumph of Verse over time. The poet immortalized the beauty of his friend in his verse. Whenever the poem will be read the beauty of his friend would be revived. And this poem will keep his friend everlasting in this world and he will be living forever through his poem.