Thanks to the Chorus, we get the lowdown on Faustus right off the bat. We know his background, what he's like, and the fact that he's one smart cookie.
But they also tell us that he became "swoll'n with cunning, of a self-conceit" (Prologue.19), in other words, proud and arrogant. Smart, proud, and arrogant? You don't get much more direct than that.
Faustus does one big deed in the play that sets everything in motion: he makes a deal with the devil. From this action, we learn that he's hungry for power, wealth, and knowledge beyond what he can just get from books.
Yet, almost as soon as Faustus has made this decision, he begins to re-think it, wondering if perhaps he doesn't want to take a stab at winning heaven after all. So we know the guy's a big thinker, too. But he's also easily distracted—and allows himself to be swept up in the delights the devils provide. That means that he's attached to worldly things like money, sex, and power. And that attachment is much stronger than his nerdier side, which would probably be more inclined to think things through.
Speech and Dialogue
If there's one point we'll emphasize in this section, it's that important characters speak fancily, while the regular folks use plain old prose.
What do we mean? Well, in important scenes between major characters, such as the interactions between Faustus and Mephistopheles, the dialogue occurs in blank verse (for more on this, see "Writing Style"). When secondary, mainly lower class characters speak, it's in prose.
Plus, the commoners' speech is peppered with interjections, abbreviations, and slang, like this line from the peasant barfly Dick: "That's like, faith! You had best leave your foolery, for, an my master come, he'll conjure you, faith" (2.2.15-16).
We know, as soon as we hear this guy speak, that he's uneducated in comparison to characters like Faustus, the nobles, and the Scholars, who prefer their musings metrical.