In the famous proviso scene in act 4, Millamant and Mirabell discuss the conditions under which they would be prepared to get married. On the face of it, it would appear that a relationship so completely hedged about with conditions is utterly devoid of love; to the uninitiated, the proviso scene seems like a discussion between two lawyers haggling over the finer points of a contract.
Yet in actual fact, Millamant and Mirabell are very much in love. It's simply that in keeping with established conventions they conduct themselves with nothing less than the expected level of decorum. Here, as in many Restoration comedies, a conversation between a man and a woman develops into a battle of wits, an opportunity for both parties to display their verbal dexterity. In such a battle, there is invariably a winner and a loser. Crucially, however, the proviso scene in The Way of the World departs from this dramatic convention. In this case, both sides win in that they agree to abide by the conditions they've set down together.
And the proviso scene doesn't just play with dramatic convention, either; it subverts the norms of polite society by showing that a woman can be the equal of any man. The very idea that a woman can lay down conditions for being married is subversive, to say the least. In so-called polite society at that time, women would've been expected to do as they were told in matters relating to marriage as in much else. Yet here we have Millamant making demands of her future husband, albeit in a spirit of mutual love and respect.
Though she may be very far from approaching contemporary ideals of liberated womanhood, Millamant, by insisting on certain conditions to safeguard her independence after marriage, challenges the prevailing gender relations of her age. And that in itself is significant.