It's called the "Triple Filter Test"

In ancient Greece, Socrates was a great philosopher and
widely acclaimed for his wisdom. One day, a friend ran up
to him excitedly and said, "Socrates, do you know
what I just heard about one of your students called Plato?"
"Wait a moment," Socrates replied. "Before you tell me anything,
I' would like you to answer a few test questions.

It's called the Triple Filter Test".

―Triple filter?" asked the friend.

"That's right," Socrates continued. "Before you talk to me about my student, I am going to ask you three questions.
The first Filter is Truth. Have you made absolutely sure
that what you are about to tell me is true?"

"No," the man said, "actually I just heard about it and..."

"All right," said Socrates. "So you are not sure if it's true or not."

Now let's try the second filter, the Filter of Goodness.
Is what you are about to tell me about my student something good?

"No, on the contrary..." said the man.

"So," Socrates continued, "you want to tell me something bad about him, even though you're not certain it's true?"

The man shrugged, a little embarrassed.

Socrates continued. "You may still pass the Triple Filter test though,
because there is a third filter - the Filter of usefulness.
Is what you want to tell me about my student going to be useful to me?"

"No, not really..."

"Well," concluded Socrates, "if what you want to tell me is neither True nor Good, nor even Useful, why tell it to me at all?"

The man was defeated and ashamed.