[Boromir88]

Originally Posted by Pitchwife

Exactly; and therefore, if it was absolutely unavoidable that one of the Steward's sons had to go on that errand, Denethor would have trusted Boromir more to represent Gondor's best interests (as he saw them!) in dealing with those tricky wizards and halfelves than Faramir, who was too much of a 'wizard's pupil' already for his father's taste.

Well, Denethor, in truth was highly reluctant to let Boromir go, and only gave in when Boromir would not be "stayed."

"Loth was my father to give me leave..."~The Council of Elrond

If you think about it, the eastern side of Osgiliath had just been taken by Sauron. Boromir was the "Captain-General" of Gondor, and with Sauron already making the first strike, I doubt Denethor would have been thrilled with the idea of sending the Commander of his army to seek answers to some trippy riddle. At least, at the time when he was approached by Boromir and Faramir, he doesn't appear to know anything about the riddle. (It took Faramir a while to figure out that Isildur's Bane wasn't referring to the orc-arrow that slew him). So, I've never had the same interpretation of the "scene" as Jackson did in the movies, where Denethor pulls Boro aside to make him as some kind of agent for Gondor. I think Boromir was just so annoying and wouldn't shut up, Denethor was more like...ARG ALRIGHT ALRIGHT GO! When Faramir doesn't bite his tongue and reminds Denethor it was he who gave Boromir leave:

"Stir not the bitterness in the cup that I mixed for myself,"...~The Siege of Gondor

Originally Posted by Bêthberry

In short, I think Boromir is full of himself and that's what makes him insist he take the journey, believing that he alone can do the task.

I've been trying to unravel Boromir's complicated character ever since I read the story. Granted, it turns out to more a gushy man-crush for Sean Bean's performance, which I think in many ways "softens" the book Boromir. The movies concentrated on the best part of the character, the troubled and conflicted man who "fell," but in the end redeemed himself. In the forefront of the books, you see his arrogance and at times very childish, immature, behavior. Tolkien in one letter calls him the "bossy brother" of Faramir, and that could be a hangover from the earlier drafts where Boromir becomes Aragorn's rival in Minas Tirith.

Although, there is far more to Boromir than his pride and big-brother bossiness:

"Your news is all of woe!" cried Eomer in dismay. "Great harm is this death to Minas Tirith, and to us all. That was a worthy man! All spoke his praise. He came seldom to the Mark, for he was ever in the wars on the East-borders; but I have seen him. More like the swift sons of Eorl than to the grave Men of Gondor he seemed to me, and likely to prove a great captain of his people when his time came."~The Riders of Rohan

...and Pippin grazing at him saw how closely he resembled his brother Boromir - whome Pippin had liked from the first, admiring the great man's lordly and kindly manner.~The Siege of Gondor

Certainly high praise from Eomer comparing him to the "swifts Sons of Eorl" and admiration for a "lordly and kindly manner" from Pippin, should warrant some good credit to Boromir's character than simply an arrogant, bossy knumbskull.