One of the great mysteries of the Zelda series is the Triforce of Courage. Does anyone really know what it does? Does it do anything? Does it give Link strength? Can it mince onions??
My first assumption was that the Triforce of Courage - get this - gives Link courage. Yet after I thought about it for a while, I found the concept a bit confusing. Much like wisdom, courage is not something physical that can be touched. Wisdom, however, is more easily defined.
"Courage is almost a contradiction in terms: it means a strong desire to live taking the form of readiness to die."
- Gilbert K. Chesterton
Courage is not being fearless. If one was fearless they would not need courage, because nothing would be a mental challenge. Therefore, the Triforce of Courage does not make Link immune to fear, upset stomach, sweaty palms, and all the other fun stuff that comes along with being scared out of one's mind.
Courage, I would say, is being able to face one's fears in order to do what is right. Perhaps the Triforce gives Link the strength to go on, or boosts his self-confidence.
If you've read through Emotionless, you know that there are times in the game where he expresses shock. And, if he wasn't afraid of anything, he wouldn't be shocked, right? Personally, I like the fact that Link's just as freaked as the player is when it's discovered he's engaged to Ruto. It makes it easier to relate to the character and makes them seem more human.
Link possessing the Triforce of Courage makes the story more realistic, as it is hard to believe a normal individual could complete such tasks. ...And that last sentence was a bit odd, considering we're talking about a video game that takes place in an alternate dimension, meaning most things aren't realistic. But anyway...
I shared what I believe the Triforce of Courage does not do, yet I think we are all still in the dark on what exactly it does do. The Wind Waker tells us that after Link entered Termina he lost the Triforce of Courage. Perhaps his quest in Termina was not as severe as the one in Hyrule (um...eh?), but I really didn't notice any kind of change in anything. Although I don't know what I'd be looking for, considering I don't know what Courage freaking DOES.
Perhaps Courage is more of a symbol than an actual working talisman. I'd like to think it actually did something for Link, but maybe it is just a sign that he holds, and is worthy of holding, a piece of the Triforce. He may already possess an extensive amount of courage and therefore is most likely to be chosen as the keeper of the Triforce of Courage.
The same idea may be applied to Zelda, as she was also chosen to hold a piece of the Triforce. On the other hand, power, in terms of the Triforce of Power, is not something one is born with. Ganondorf's power was that of strength and manipulation, not the born-into-power that Zelda has. It leads me to believe that the Triforce only enhances one's abilities if it is that person who touches it. Ganondorf forcefully took Power, and it helped him to become an evil overlord. Link and Zelda, however, were chosen. They were chosen for a reason, most likely the fact that they already showed signs of wisdom and courage and the Triforce pieces found them most suited.