In "To His Coy Mistress," two arguments run parallel to each other: The speaker uses the carpe diem theme to try to persuade his beloved to indulge in the physical pleasure of love; and beneath the surface of the frivolous subject of courtship, the poet makes a serious point about the fleetingness of human life.
"... I would
Love you ten years before the Flood,
And you should, if you please, refuse
Till the conversion of the Jew"
The speaker makes biblical allusions in the lines above. He refers to the story of the great flood from the book of Genesis and the conversion of the Jews, which, it is said, will occur shortly before the Last judgement. These allusions are meant to convince the speaker's mistress that he would court her at a slower pace if he had more time. But that pace is not possible because life is too short.
"Thy beauty shall no more be found,
Nor, in thy marble vault, shall sound
My echoing song; then worms shall try
That long-preserved virginity"
Here the speaker argues that the chastity his mistress is trying to preserve will be nothing but the food of worms after death. He is trying to persuade her to enjoy carnal pleasure while she is young.
"Now therefore, while the youthful hue
Sits on thy skin like morning dew"
In these lines, the speaker is reinforcing his point that the pleasures of youth are to be enjoyed while still young. The final couplet seals the argument with a concluding <em>thus</em>:
"Thus, though we cannot make out sun
Stand still, yet we will make him run."
In these final lines, the speaker acknowledges that he can't make time stop, but if he and his beloved enjoy the time they have to the fullest, then time will at least have a tough job keeping up with them.