Sir Walter acts as a foil to both Captain Wentworth and to Anne Elliot. As a vain, pretentious, and stubborn baronet, he maintains personal qualities that are abhorrent to Austen's protagonists. Selfish and self-absorbed, he is unable to think past himself and his own immediate desires. Yet Sir Walter is not at all evil or ill-inclined; rather, he is comically ridiculous, a caricature of the old, titled class. Sir Walter allows Austen to poke fun at the declining aristocracy. With the rise of industry in Great Britain beginning in the late eighteenth century, old, titled families were forced to consider accepting the nouveau riche into their circle. Such industrial magnates and wealthy merchants who had made their fortunes trading with the colonies had large amounts of money, and could afford to challenge the importance of birth in social interaction. Sir Walter's strong attachment to the significance of birth appears antiquated in the new century of progress.
Sir Walter is an impractical man; his habits of lavish spending and his strong desire to maintain appearances threaten the very future of the Elliot family. This is a grave character flaw, which Anne does not easily forgive. But his vanity is perhaps the defining character of Sir Walter. With a dressing room surrounded by mirrors, a Baronetage book treasured for its description of the Elliot family, and a predilection to be seen only with attractive and socially important people, Sir Walter is the very image of conceit. Yet, Sir Walter's ridiculousness highlights the fact that his kind is no longer the preferred version of manliness. He is an effeminite man, one who would shy away from the sun for fear of a negative reaction of his complexion. In stark contrast is the gallant, brave naval officer, Captain Wentworth, a very different and more modern ideal of the British gentleman.