Jaques is one of Duke Senior's attendants and he's got a well-deserved reputation for being "melancholy." We might even say that Jaques enjoys being sad and mopey because he purposefully seeks out experiences that are depressing.
And just about everything depresses this guy. "I can suck / melancholy out of a song, as a weasel sucks eggs," he brags (2.5.12-13). In other words, if Jaques were a modern teenager, he'd be wallowing around his bedroom on a Friday night listening to depressing music on his iPod while everyone else was out having fun. Seriously. Jaques even refuses to take part in the wedding festivities at the end of the play. While everyone else is getting down on the dance floor, Jaques announces that he's just going to go back to Duke Senior's "abandoned cave" (5.1.206).
You're probably thinking "Gee, this guy sounds even more depressed than Hamlet." You're so right, Shmoopster, but the difference between Jaques and Hamlet is this: Hamlet has got a few things to be bummed about (like the fact that his uncle killed his dad, married his mom, and told him to stop being a baby about it). What's Jaques got to be sad about? Not much.
Yet that doesn't stop Jaques from seeing himself as a moody philosopher with brilliant insight into humanity. In fact, he says he wants to be a licensed fool like Touchstone. (Basically, a "licensed fool" is a court jester with an actual license to say whatever he wants, like Feste from Twelfth Night). But is Jaques as smart or insightful as he thinks he is? We think not.
What? You want an example? Fine. Check out a sampling of Jaques's most famous speech:
All the world's a stage,
And all the men and women merely players.
They have their exits and their entrances,
And one man in his time plays many parts,
His acts being seven ages. [...] (2.7.146-150)
When Jaques declares that "all the world's a stage," he's right. Life is a lot like one big theater performance and there's a lot of theatricality involved in day-to-day living. (Just ask cross-dressing Rosalind.) That said, this concept was already a big fat cliché by the time Jaques said it, so he ends up sounding like a big poseur. (Go to "Symbolism, Imagery, Allegory" for more on this.)
We sort of see why Nobel Prize-winning playwright George Bernard Shaw found him "exasperating" and hated Jaques's penchant for "sham moralizing." On the other hand, we think the great thing about the character is the fact that Shakespeare knows Jaques is full of bologna. Why else would Big Willy name the guy "Jaques" (pronounced jay-kweez), a word that basically means "toilet"? It seems like Shakespeare is pretty up-front about the fact that Jaques is full of crapola, don't you think?