The speaker of the poem argues that "Love's not Time's fool." What does he mean by this? Do you agree?The poem is Sonnet 116 by William Shakespeare

"Love's not Time's fool" captures the controlling metaphor of this Shakespearean sonnet as all other lines reinforce this sentiment:  "Love is not love" if it changes with the corrosive power of time, "Love alters not with his brief hours and weeks," "it is an ever-fixed mark."

There is, however, a flaw in the poet's logic.  For, in the final couplet, he challenges his reader's to disprove his argument as though it is logically sound.  But, the first lines establish a condition to this reasoning: 

Let me not to the marriage of true minds/Admit impediments.

So, if the reader does not accept this condition and does, in fact, admit impediments, or obstacles, to love, then the argument of the poet is not unequivocably reasonable, and may not be "an ever-fixed mark."