In Harry Potter and the Half-Blood Prince, Chapter 17, Dumbledore and Harry are using the Pensieve to experience the vital Slughorn memory (which was tampered with), and Harry is instructed to collect the untampered memory.

My question: How did Dumbledore collect the tampered one in the first place?

In that same chapter:

“you don’t need me — you could use Legilimency . . . or Veritaserum. . . .”
“Professor Slughorn is an extremely able wizard who will be expecting both,” said Dumbledore. “He is much more accomplished at Occlumency than poor Morfin Gaunt, and I would be astonished if he has not carried an antidote to Veritaserum with him ever since I coerced him into giving me this travesty of a recollection.

Is this implying that Dumbledore used Veritaserum to force the memory out of him? I suspect not, given that it was tampered with (i.e. not truthful). So, what did happen? How did Dumbledore coerce him?

2 Answers 2


Dumbledore does not explain how did he obtain the memory but after carefully reading the text I think the most probable explanation is that he simply asked Slughorn at the right moment.

Harry Potter and the Half Blood Prince, chapter 17:

"As you might have noticed," said Dumbledore, reseating himself behind his desk, "that memory has been tampered with."

"Tampered with?" repeated Harry, sitting back down too.

"Certainly," said Dumbledore. "Professor Slughorn has meddled with his own recollections."

"But why would he do that?"

"Because, I think, he is ashamed of what he remembers," said Dumbledore. "He has tried to rework the memory to show himself in a better light, obliterating those parts which he does not wish me to see. It is, as you will have noticed, very crudely done, and that is all to the good, for it shows that the true memory is still there beneath the alterations.

So most probably Dumbledore just cornered Slughorn and asked him about Tom Riddle and Horcruxes.

Slughorn could have lied but I guess he did not dare lying directly to Dumbledore.

So looks like Slughorn choose another option - to quickly falsify the memory before giving it to Dumbledore and thus it was a very crude falsification.

Why is it unlikely that he used Legitimency? Because it is very intrusive and very humiliating for the person it is used on. Doing this against Slughorn's will would mean the end of their friendship and also Slughorn will never again agree to talk or work for Dumbledore.

  • 1
    I don't think it was Legilimency either, but not because I think Dumbledore is above doing that to one of his "friends", though that would be a factor, instead it's clearly stated in my question's quote that the whole reason Harry's suggestion of "Legilimency" gets rejected is because Slughorn is far too much of an accomplished wizard, skilled in Occlumency, to attempt to try that on him. Seems like an instant disqualifier. Dec 3, 2016 at 21:45
  • 4
    “Asked” seems like too mild a term, given that Dumbledore said that he “coerced” Slughorn.   I would guess that Dumbledore (using his authority as headmaster) ordered or requested Slughorn (who, in effect, worked for Dumbledore) to divulge the memory, perhaps threatening disciplinary action if he refused. Dec 3, 2016 at 22:09
  • @PeregrineRook PEREGRINEROOK! THIS IS NO PLACE FOR A HOBBIT! —uh.. So, according to you, the memory was acquired whilst Slughorn worked for Dumbledore. When do you suppose (roughly) that happened? You're not suggesting it happened during the events of HBP, after Dumbledore and Harry visited his hideout house and Dumbledore hired him, are you? For some reason I had assumed he had acquired the memory long before then - his reluctance to work at Hogwarts again in the first place has many factors and reasons, but Dumbledore's coercion seemed like one of them, to me. Dec 4, 2016 at 10:43

I believe he used Legilimency.

In Half-Blood Prince, after showing Harry the memory of Morfin Gaunt in the Pensieve, Dumbledore says:

“Yes, but it took a great deal of skilled Legilimency to coax it out of him,” said Dumbledore, “and why should anybody delve further into Morfin’s mind when he had already confessed to the crime? However, I was able to secure a visit to Morfin in the last weeks of his life, by which time I was attempting to discover as much as I could about Voldemort’s past. I extracted this memory with difficulty. When I saw what it contained, I attempted to use it to secure Morfin’s release from Azkaban. Before the Ministry reached their decision, however, Morfin had died.”

This shows that Legilimency can be used not only to "read minds" (sorry, Professor Snape), but also to extract memories from someone else, even against his/her will, and store them in such a way that they can be later retrieved and seen in a Pensieve.

  • Doesn't seem to add up, considering the quote I included in the question. Harry even suggests Legilimency (because Dumbledore talked about using it on Morfin earlier) Dec 3, 2016 at 19:36
  • @GhotiandChips my guess is that your quote simply means that Dumbledore couldn't have used Legilimency again, because Slughorn would have been prepared for that. Maybe he caught Slughorn by surprise, so Slughorn didn't have time to shield himself from Legilimency. As far as I know, Legilimency is the only way (supported by canon) to extract someone's memories and read them in a Pensieve.
    – A. Darwin
    Dec 3, 2016 at 19:41
  • re: "used Legilimency again">That would be the logical assumption to make, but we'd have to first assume that the first assumption is true (that he used it in the first place). Also, again, in the quote included in the question, it is implied by Harry's question and Dumbledore's response that Veritaserum is another way, so Legilimency isn't the only known, canonically supported way to extract a memory. Dec 3, 2016 at 19:44
  • based on the quote I gave in the question, alone, the more likely of the two methods that he used the first time was Veritaserum, just by examining the sentence. He's saying Slughorn is far too accomplished to succumb to Legilimency, so that isn't an option, and that he would be "astonished" if he doesn't carry an antidote to Veritaserum ever since he coerced him. I'm not saying that makes it the correct answer, but if we're basing it on that alone, I would place Legilimency as least likely of the two. Dec 3, 2016 at 19:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.