Integral to One's Self.

Sorry I've taken an age to get to this one. Things like happening all at once, and I'm lazy. :P

Trust, honesty and integrity. Perhaps before I wax too lyrical on these three, I should briefly on how I define them. Essentially; trust is what you put in someone else when they're honest with you because they have integrity. I'll expand on that in bits within this post.

Trust is sometimes called the basis of all relationships. After all, if you have no trust in someone (on some level, at least - there are many levels of trust), how could you relate to them?
And many try to seek out the trust of other people - it's one of their foundational things, that they have to do. It can become an obsession for some. And what starts as a search for friends can easily spiral downwards into something quite desperate - a cry for attention, or a deep desire to be loved or valued. In some senses, these aren't inherently bad things in and of themselves; but they can sometimes drive people to a point that is not too great.

Honesty is an interesting one. It can be taken to some very different places. You can have a sort of radical honesty, or be a bit less...harsh.
Radical honesty teaches to be always honest, even when it seems blunt, direct or impolite. Fairly simple idea, quite difficult to keep up. Depending on your personality, of course. However, this sort of honesty can lead to a rift between you and other people; this won't always be the case, and some have and do use this successfully, but it's very difficult to pull off.
But just because you always tell the truth, doesn't mean you have to be blunt, rude or critical. You can instead try to be helpful; uplifting and more choice about the fashion in which you tell the truth. That doesn't mean sugarcoating something that hurts so that it goes down easier; but it does mean helping someone get up from the blow.

Integrity is a bit more difficult to put your finger on. It's like a sort of morality, or moral fibre - a sense of needing to do what's right, because you should. Something like that.
And honestly, it's a bit hard to fault. Perhaps the best way of putting it is that, even if you have this integrity and you always do something for the right reasons - you can still do the wrong thing for the right reasons. Sometimes other things have to come first, like trusting someone else's ability, or someone else's integrity. That's where, really, these three kinda weave together.

Because each of these three by themselves can be good, but you really need all three - they're made for each other, that's how they work at their best.

So essentially, each of these can have their individual drawbacks, but these are largely overcome when used together.