How do you know what you did was 'good virtuous ethical right moral' et al?

Suppose it is obvious that someone in need should be helped.

 A utilitarian will point to the fact that the consequences of doing so will maximize well-being, a deontologist ("obligation, duty" is the normative ethical position that judges the morality of an action based on rules) to the fact that, in doing so the agent will be acting in accordance with a moral rule such as “Do unto others as you would be done by”
 and a virtue ethicist (those of a leftist bent) to the fact that helping the person would be charitable or benevolent (however one has to deconstruct the nature of benevolence is it no more than acting out Darwinism?)

 Whereas consequentialists will define virtues as traits that yield good consequences and deontologists will define them as traits possessed by those who reliably fulfill their duties, virtue ethicists will resist the attempt to define virtues in terms of some other concept that is taken to be more fundamental

Why did you give that tramp money
I did it because it is charitable, good, an ethical, virtuous thing to do
So you carried our the act of A because of B 
If you say so
But where does the B that impelled you to act come from, what is its etymology, 
its history how was it constituted etc?
I just know that was a 'good' act
But that it was a 'good' act is an opinion not a fact.
I am not interested in facts
Yes, I can see that.