...From women's eyes this doctrine I derive.
They sparkle still the right Promethean fire;
They are the books, the arts, the academes,
That show, contain, and nourish all the world;
Else none at all in aught proves excellent,.
Then fools you were these women to forswear,
Or, keeping what is sworn, you will prove fools.
For wisdom's sake, a word that all men love,
Or for love's sake, a word that loves all men,
Or for men's sake, the authors of these women,
Or women's sake, by whom we men are men--
Let us once lose our oaths to find ourselves,
Or else we lose ourselves to keep our oaths.
Love's Labour's Lost promises us a love story, and delivers a bitter pill. The setup is right out of some Medieval rom-com: The King of Navarre and his retinue, Dumaine, Longaville, and Berowne, take an oath to forswear women for three years so they might devote themselves to serious study. Only Berowne sense that this is a bad idea, and predicts that they'll all break their oaths before long:
Necessity will make us all forsworn
Three thousand times within this three years' space:
For every man with his affects is born,
Not by might mast'red, but by special grace.
If I break faith, this word shall speak for me,
I am forsworn "on mere necessity."
The predictable thing happens next: women arrive, in the form of the Princess of Aquitaine and her retinue, and the King and his men fall deeply in love, each with a different woman. Each man tries vainly to woo his love's object while keeping it hidden from the others. This leads to a very funny scene in which each male character enters reading aloud a love poem of his own devising, and then, when he hears the next one approaching, scuttles into hiding. Each poem is worse and worse, until finally there are three guys hiding, to various degrees of each others' awareness, listening to Longaville's shitty poem, which begins "On a day--alack the day!-- / Love, whose month is every may, / Spied a blossom passing fair / Playing in the wanton air."
Once they spend a little while shaking their fingers at each other, the menfolk put their heads together to try to woo the Princess and her maids. Though his prediction is proved correct, Berowne comes in for the worst criticism, because his beloved, Rosaline, is supposedly exceedingly ugly and "black," or dark-skinned. As the King says, "I'll find a fairer face not washed today." This echoes with the presence of the "dark lady" of the sonnets, who is equally ugly ("My mistress' eyes are nothing like the sun"), equally crass and sordid, and yet whose attraction is--for Berowne as for the speaker of the sonnets--unavoidable.
Love in Love's Labour's Lost has all the dressing of poetry and courtly romance, but at its bottom, it's like Berowne's love for Rosaline: inexplicable, physical, almost bestial. Rosaline treats Berowne with bitter jabs, and he is helpless. The other women, sensing that the men's sincerity is questionable, play a trick on them by switching their masks. (Why are they wearing masks? Why not?) The men, as they suspect, cannot tell one from the other without their physical likenesses. The play which seemed, at the beginning, to set up a predictable course toward resolution, seems to suggest that the dynamics of human love and sex are irresolvable: men obsess, and women rebuff.
The play ends when the real world interrupts the childish play of love: a messenger comes to inform the Princess that her father has died. The King, like an entitled MRA, demands to be loved: "Now, at the latest minute of the hour / Give us your loves." The women impose harsh penitences in exchange, perhaps knowing that the men will not keep them: The King must spend a year as a hermit, and Berowne, healing the sick. Some sources suggest there is a lost sequel to the play--Love's Labour's Won--perhaps in which the King, Berowne, and all the rest complete their hairshirt requirements and win the ladies they sought to woo. But I doubt it.