For all his skill with flare guns and tracking, The Man is really a big softie. Think of a mean biker dude with "Mom" tattooed on his bicep. Think of a skilled medieval crossbowman who likes to write love poems on the side. Think of a cattle rancher who likes to grow rose bushes. Really, think of any tough person with a sensitive side. Of course, The Man is more complicated than these caricatures – but they're a good place to start.
One of the first things we notice about The Man is his devotion to The Boy. Remember the first sentence of the novel? "When he woke in the woods in the dark and the cold of the night he'd reach out and touch the child sleeping beside him" (1.1). The Man identifies his son as his "warrant" – which means the child provides him with a reason to live (3.1). The rest of the novel bears this out. The Man's thoughts always return to The Boy. Everything The Man does seems to be done out of consideration for The Boy – to educate him, feed him, keep him safe, protect him, or keep him warm.
The Man is utterly devoted to his son. The isolation of these two characters – the post-apocalyptic setting helps, of course – creates a special bond between parent and child. It allows for a profound closeness. And The Man's love for his son takes on a heroic quality; who else in the novel cares for anyone this way? The Man's virtues of kindness and selflessness, given the setting, become superhuman feats.
The Man's devotion to his son doesn't diminish his toughness; if anything, it only makes him fiercer. Another constant of the novel is The Man's bravery and skill. He rigs stoves, shopping carts, and torches. He carves and colors imitation bullets for their pistol. He even sews up his own wound! If pushed, he's ruthlessly violent. When one of the "bad guys" threatens The Boy with a knife, The Man responds like Jason Bourne:
The man had already dropped to the ground and he swung with him and leveled the pistol and fired from a two-handed position balanced on both knees at a distance of six feet. The man [the "bad guy"] fell back instantly and lay with blood bubbling from the hole in his forehead. (102.56)
This guy doesn't mess around – this is action hero stuff. McCarthy counterbalances The Man's devotion to his son with a ruthless streak. He sets a "bad guy" on fire with his flare gun and leaves a thief in the middle of the road without any clothes. It's ambiguous, however, whether McCarthy wants us to judge The Man's ruthlessness or praise it. Is it an expression of his devotion for The Boy and concern for his safety? Or does The Man become too much like the people he's trying to protect The Boy from?
You have to wonder how much the apocalypse and his wife's suicide have damaged The Man. He often seems burdened by the past: not only the loss of his wife, but knowing (unlike The Boy) another life before the disaster. The Boy doesn't seem burdened in the same way. He is more open and generous to those they meet on the road. There's a passage late in the novel when The Boy points out to The Man that he has to make sure they remain good and kind amidst all the world's collapse. When The Man says to The Boy, "You're not the one who has to worry about everything," The Boy responds, "Yes I am [...]. I am the one" (356). Meaning, The Boy has to make sure they make ethical choices.