Sonnet 116.

Let me not to the marriage of true minds 
Admit impediments. Love is not love 
Which alters when it alteration finds, 
Or bends with the remover to remove: 
O no! it is an ever-fixéd mark 
That looks on tempests and is never shaken; 
It is the star to every wand'ring barque, 
Whose worth’s unknown, although his height be taken 
Love’s not Time’s fool, though rosy lips and cheeks 
Within his bending sickle’s compass come: 
Love alters not with his brief hours and weeks, 
But bears it out even to the edge of doom. 
   If this be error and upon me proved, 
   I never writ, nor no man ever loved.