Fake Moody had demonstrated a killing curse on the spider in class. I have my doubts that he would risk his soul being damaged over some spider demo.

Was he not aware of the soul splitting process upon killing? Or does the soul only split upon killing human beings?

  • 4
    Is there canon evidence that soul splitting is in any way related to the killing curse? Would your soul split if you killed someone by some other means? If so, I think it's hard to claim that killing a spider (by any means whatsoever) is a sufficiently unusual event to merit soul splitting.
    – Kevin
    Dec 12, 2017 at 19:51
  • @Kevin scifi.stackexchange.com/questions/175243/… makes it clear that, in canon, it does not have to be the killing curse to split one's soul and create the horcrux.
    – DqwertyC
    Dec 12, 2017 at 20:05
  • Barty Crouch Jr. does kill a human being as well, later, btw--he murders his father.
    – Kitkat
    Dec 12, 2017 at 20:52
  • 1
    Do we even have any information in canon of why splitting the soul is undesirable? I mean, Slughorn didn't think it was a good idea, but he didn't like murder either. So maybe a ripped-up soul isn't so bad to an evil person. Dec 12, 2017 at 21:15
  • I always assumed Slughorn found the idea of murdering people just for the sole (heh) purpose of putting part of your soul into a Horcrux (self-preservation) unpalatable. Would a split soul just return to its host if there was no other suitable vessel? In any event, if splitting the soul itself is bad and if killing insects could result in such splitting, it would likely be the first lesson they taught to every magical child.
    – delinear
    Dec 13, 2017 at 13:03

2 Answers 2


There is no evidence in canon, that the killing of animals can split your soul. The splitting of the soul is caused by murder, which according to Merriam Webster is

the crime of unlawfully killing a person especially with malice
Merriam Webster - Murder

Barty Crouch Jr. isn't killing a person, and according to the Halfblood Prince, the curse itself doesn't split the soul. Instead, a person's soul is split apart by

By committing murder. Killing rips the soul apart.
Half-Blood Prince - Chapter 23: Horcruxes

So no, killing an animal as a demonstration wouldn't rip apart someone's soul, and Barty Crouch Jr probably knew that.

  • So then, for spiders AK is no different than pesticide? Dec 12, 2017 at 20:09
  • @VadzimSavenok I doubt anyone would. That's pretty overkill. And what if your wand malfunctions or hits someone else. I bet there are specialized curses for dealing with those sort of pests. Dec 12, 2017 at 20:12
  • But what if said spider was a transfigured human and barty didnt know it? Think about it. You kill a spider and then your wife enters and says: oh noes! Poor Gram Berta! I told her transfiguring her so she coud win in the hide and seek against our son would be a bad idea...
    – user68762
    Dec 12, 2017 at 20:12
  • ...but you knew all along that it's Gram Berta and took your chances to get away with it, claiming you had no idea. So... you're guilty, your soul is fractured and black as sin. But then, she is revived by that annoying muggle bf of your daughter - the guy is mumbling something about 'CPR' and 'epinephrine injection' and after just a few minutes Berta's heart beats again. How is your soul looking now?
    – user68762
    Dec 12, 2017 at 20:33

It almost certainly didn’t.

It’s unlikely killing insects would affect someone’s soul. Typically, killing spiders is treated very different than killing humans. Slughorn explains that it’s caused by murder specifically, not just killing.

“Well,’ said Slughorn uncomfortably, ‘you must understand that the soul is supposed to remain intact and whole. Splitting it is an act of violation, it is against nature.’

‘But how do you do it?’

‘By an act of evil – the supreme act of evil. By committing murder. Killing rips the soul apart. The wizard intent upon creating a Horcrux would use the damage to his advantage: he would encase the torn portion –”
- Harry Potter and the Half-Blood Prince, Chapter 23 (Horcruxes)

The act that splits the soul is murder, and while the “magic” definition might be different from the legal definition, killing spiders is probably still not considered murder. Splitting the soul is clearly shown as a rare act of extreme evil. It’s unlikely that killing spiders (something many wizards likely do) would be enough to cause such a thing “against nature”. In addition, if killing spiders would be enough to create Horcruxes, more people might be likely to be willing to do it.

Later, Slughorn also says it’s bad enough to think of killing one person, implying it is human death (or at least the death of something humanoid) required to create a Horcrux.

“Merlin’s beard, Tom!’ yelped Slughorn. ‘Seven! Isn’t it bad enough to think of killing one person? And in any case … bad enough to divide the soul … but to rip it into seven pieces …”
- Harry Potter and the Half-Blood Prince, Chapter 23 (Horcruxes)

Slughorn also would likely not feel so strongly about Horcruxes if he thought they could be made by killing spiders, since the majority of people don’t have much moral qualms about killing spiders.

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.