MORE: (Draws up his sleeve, baring his arm) There is my right arm [...] Take your dagger and saw it from my shoulder [...] if by that means I can come with Your Grace with a clear conscience. (1.525)
This is a littlemelodramatic, but we'll cut More some slack. See, he's actually a pretty conservative guy: he follows the law to the letter and has a great deal of respect for his boss, King Henry. That's why he's so confused about what to do regarding the King's divorce. No matter what he chooses, he'll end up betraying the political system he's spent his life defending.
HENRY: I have no Queen! Catherine is not my wife and no priest can make her so, and they that say she is my wife are not only liars...but traitors! Mind it, Thomas. (1.586)
Here, Henry is laying down the gauntlet: if More doesn't approve of his divorce from Queen Catherine, then More is a traitor. That's a serious accusation. What's more, there's probably nothing that makes the rule-abiding More more nervous than the thought of being known as a treacherous traitor and unrepentant law-breaker.
MORE: [...] The currents and eddies of right and wrong [...] I can't navigate. [...] But in the thickets of the law, oh, there I'm a forester. I doubt there's a man alive who could follow me there. (1.690)
Although he quietly disapproves of the King's plans to divorce Queen Catherine, More is convinced that his superior knowledge of the law will keep him safe from any shady political maneuverings. In his head, that would be like someone trying to beat the Incredible Hulk in a "Getting Angry" contest. Not going to happen, chumps.
ROPER: So now you'd give the Devil benefit of the law!
MORE: Yes. What would you do? Cut a great road through the law to get after the Devil? (1.693-694)
This makes us think of a famous saying: those who would trade their freedom for protection deserve neither. In other words, if you get rid of good laws in order to catch bad people, you're only helping those bad people reach their goals, because the final result will be that it will become easier to get away with bad things now that the laws have been flattened.
MORE: Oh? (Advances on ROPER) And when the last law was down, and the Devil turned round on you, where would you hide, Roper, the laws all being flat? (1.696)
Sorry, Roper—you just got served, son. Here, More continues his train of thought from the previous quote, arguing that bypassing laws to do "good" always has negative consequences. Just think about Cromwell. He proves more than willing to throw the law away when it suits him, and we know how that ends up (hint: with his execution).
MORE: [...] I stand on the wrong side of no statute, and no common law. (Takes MEG'S hand too) I have not disobeyed my sovereign. I truly believe no man in England is more safe than myself. (1.711)
This is More's brilliant legal defense: complete and utter silence. And you know what? It almost works. Due to the intricacies of the British legal system, More can only be executed if he admits to committing treason. If he doesn't, he might be able to create enough reasonable doubt to keep himself for getting that gruesome neck-level haircut. It's a clever move.
NORFOLK: [...] The Pope's a Prince, isn't he?
MORE: He is.
NORFOLK: And a bad one?
MORE: Bad enough. But the theory is that he's also the Vicar of God the descendant of St. Peter, our only like with Christ. (2.101-104)
This is actually pretty similar to More's thought process regarding King Henry. Although More disagrees with many aspects of the King's political strategy, he still follows him because them's the rules. The same goes for the Pope. Man—More can't even look at religion without donning his lawyer cap.
MORE: [...] Signor Chapuys tells me he's just made a "tour" of the North Country. He thinks we shall have trouble there. So do I. (2.127)
Here, More is warning Norfolk about a possible armed uprising of loyal Catholics that he heard about from Chapuys. If this doesn't prove that More is sincerely devoted to the English government despite his religious reservations, then we don't know what will.
CROMWELL: [...] You're absolutely right, it must be done by law. It's just a matter of finding the right law. Or making one. (2.232)
We can't help but think back to More and Roper's conversation about the devil whenever Cromwell sticks his slimy little head into the scene. Dude might as well be sporting a pair of horns, wielding a pitchfork, and cackling about the eternal fires of hell. Do you think Cromwell's actions—or his mindset—might be construed as "evil"? Sure, Cromwell doesn't go around killing babies, but maybe his actions are what "evil" looks like in the real world? Food for thought.
MORE: The law is not a "light" for you or any man to see by; the law is not an instrument of any kind (2.714)
More has the perfect quip for any situation, and this is no exception. He also makes a great point—to think of the law as something to be used makes it inevitable that the law will be exploited at some point in the future.