The concept of guilt appears in the oldest known work of literature, the Epic of Gilgamesh. All epics have a philosophical aspect. Interestingly, a sense of guilt comes to Gilgamesh by way of contact with a character named Enkidu, who is sort of like Gilgamesh's wild-born twin.

The message appears to be that guilt does not come from civilized city-life. It's emerges from the depths of our hearts (in which our wild roots are still evident.)

I think guilt is a complex notion in ancient thought. Guilt as a cause, as shame, as a defiance of fate, as complicity with fate (determinism). Free will as reasoned choice versus desire, spontaneity, a break in a series.

Guilt as a response to our failure to live up to our own will. The will as a separate facility of the mind, is I think a discovery which Hanna Arendt attributed it Christianity, specifically Paul The Apostle.

I've never understood it. As I rarely if ever intentionally do harm and later regret it, I never feel any guilt. On the rare occasions where I intentionally set out to do harm, why would I feel guilt for fulfilling my will? To feel guilt is denial. A denial of the self.

I do not trust guilt. It seems to be an emotion that people display so they can avoid responsibility for their actions, such as in front of a judge or other figure of authority. Do people actually 'feel' this? Or are they just worried at the possible ramifications of their poorly judged decisions and actions?

I think guilt can be a positive or a negative. Guilt can be an impetus for change.

But, I've also come to understand that when people feel guilty, their immediate reaction is usually to feel defensive and to start rationalizing. So, maybe it's not the best reason to change.

Perhaps a more rational vs emotional response would be something like, "I don't like the consequences of X. So, I'm going to find a way to stop doing X."

@anonymous.
I do not see rationalising as the problem here. What use is the feeling if you do not think through the problem. And that is exactly the result that leads to your last sentence.
All these responses that lead to emotional angst are negative if you do not learn and change according to practices that made you feel that way. Regret, being apologetic are all useless. Being able to explain what has happened and knowing how your actions have contributed to harm is vital.
Regret nothing. Never apologise. Learn through explanation.

What use is the feeling if you do not think through the problem... Being able to explain what has happened and knowing how your actions have contributed to harm is vital. — charleton

Well said. Good point.

Thanks. This is why I never apologise. I always offer an explanation and reassure concerning my good intentions.