The best example where these three paths intersect can be found within the philosopher’s magnum opus, The Republic. It is near the end of Book VI that Plato, through the voice of Socrates, begins to make his case for the existence of an ultimate source of virtue that shines upon all existence and grants us the ability to live wisely and virtuously.
For Plato, this grand source of all morality is known simply as “The Good.”
This latter half, which later philosophers (especially Immanuel Kant) would refer to as the phenomenal world, is of great importance to Plato.
Much of the philosopher’s ideas on ethics is dependent upon the existence of this conceptual world.
Finally we arrive at the last segment on the line, the portion that corresponds to the realm of the forms and, more importantly, the form of The Good.
Was Hitler good at instigating a second world war? Yes.
Was Hitler good at creating a propaganda machine? Yes.
Was Hitler a good painter? Maybe.
But back to our original question. Was Hitler good? The answer, rather obviously, is no.
While Hitler was good insofar as he was a dictator or a public speaker, we can say rather confidently that he was not Good.