What determines the power of a wizard in Harry Potter's world?

Question

It is obvious that different wizards can cast spells with different power and/or effect (same for potions). But why?

Just some observations from my side - perhaps I'm wrong for some of them:

Spell casting seems to be like playing music or painting. More or less everyone can do it and the quality depends on some factors like:

• knowledge - gained by studying
• experience - gained by practicing
• intelligence - innate and cannot be gained easily
• concentration at the moment (or ability to concentrate in general)

and last but not least

• innate ability (talent) - you either have it or not

To me it looks like that the last one is determining everything. Some wizards like Dumbledore or Voldemort just "have it" and others will never be able to reach their power no matter how hard they try. Another example - Hermione is very intelligent and has read all the books but Harry beats her in defense against the dark arts nevertheless (and no - it's not Quidditch that helps him :) ).

Answer 1

From my understanding Magic in the potterverse works as any other ability.

There's no clear explanation as of today as to what makes a human an expert in some given field. There're professional dancers that have an innate ability combined with intense training and study. Then you have some others which weren't born with that ability but developed it through even harder effort and training.

Magic works in the same way any other complex activities work, as a combination of inherent ability and training and effort. It's also a wide field meaning one may have natural ability in one part of it (i.e. Ballet) but had to train hard for another (I.e break dance) although as any other thing having a base knowledge makes further improvement easier.

We would say that Harry has a natural ability for learning new stuff, maybe as good as Hermione but he lacks the effort and dedication Hermione has. Neville doesn't have a particularly high innate magic ability but he does have an innate ability in herbology AND he likes it and puts a lot of effort into it.

There's also the factor of confidence in oneself. This is mentioned regarding Ron's quidditch abilities, or the progress made by Neville on the Secret DA classes once he gets approval and support from everyone else.

In summary, magic is like any other field or craft known to men, there are people with different innate abilities and nobody knows exactly why. The best of the best though only get there by a combination of innate abilities and hard work.

Regarding wands, I consider them as any other piece of equipment. Superior equipment enhances your ability far more than lesser equipment but it only enhances your ability. A lousy seeker will be better with a firebolt but a great seeker would defeat him easily with a nimbus 2000. Wands are the same, a great wizard will do great magic with or without a great wand and will be hindered by a lousy or broken wand but it's the equivalent of piloting a car. I'm pretty sure any F1 pilot would be able to beat me in any circuit even if I'm driving a Ferrari and he's driving a Toyota.

Answer 2

I believe the power of a witch or wizards magic has to do with their emotional state and well being.

Let me try and explain-

Lily sacrifices herself in order to protect Harry from Voldemort, a protection that Dumbledore explicitly says has to do with her love(Yes, not loving someone that much would not make you sacrifice yourself, but then you wouldn't be able to use that "old magic" anyway).

In GoF, Harry needs to draw on his happiest memory to be able to cast expecto patronum, and the happier the memory/thought, the more powerful the patronus.

Another example is when Barty Crouch Jr. explains to the students in the DADA class that even though they all pointed their wands at him and uttered the words for avada kedavra, he wouldn't get so much as a nosebleed- which I think is because none of them would truly want him dead(wanting someone to die is usually because of hate/jealousy/anger etc):

Avada Kedavra’s a curse that needs a powerful bit of magic behind it — you could all get your wands out now and point them at me and say the words, and I doubt I’d get so much as a nosebleed. - Barty Crouch Jr. -Harry Potter GoF

One more example is when Harry chases down Bellatrix in the ministry of magic after she killed Sirius Black.(Order of the Pheonix) He tries the cruciatus curse on her, which ultimately fails because he didnt have the correct "emotion" paired with that spell(he has to mean it. In other words, he must want to hurt the target, even get some form of pleasure from inflicting pain).

Hatred rose in Harry such as he had never known before;he flung himself out from behind the fountain and bellowed,'Crucio!' Bellatrix screamed:the spell had knocked her off her feet,but she did not writhe and shriek with pain as Neville had- she was already back on her feet,breathless,no longer laughing.Harry dodged behind the golden fountain again.Her counter-spell hit the head of the handsome wizard,which was blown off and landed twenty feet away,gouging some long scratches into the wooden floor. 'Never used an Unforgivable Curse before have you boy?'she yelled.She had abandoned her baby voice now. You need to mean them,Potter!You need to really want to cause pain-to enjoy it-righteous anger won't hurt me for long-I'll show you how it is done,shall I?I'll give you a lesson-' Chapter 36 The Only One He Ever Feared Harry Potter and the Order Of The Phoenix.

I am sure there are a few more examples in the books that could be used, but these are a few that I remember of the top of my head.

Dumbledore, Voldemort and Harry (Three of the main characters) all have something in common- a messed up childhood. It is my believe that because of this, their (innate) power are amplified a bit by the powerful emotions that they experience thanks to their history.

Harry had to use a memory of his parents before their tragic fate in order to create a corporeal patronus- would he have been able to do so if they were still alive and well?

Sorry for not having the relevant quotes for my claims- I will add them once I get home tonight as I do not have access to the books from work. If anyone feels they want to add the quotes- be my guest! :D

Answer 3

Why? Because you need to learn it and because wands are only as powerful as the wizards that use them.

Wands are only as powerful as the wizards who use them. Some wizards just like to boast that theirs are bigger and better than other people's.

― J.K. Rowling, Harry Potter and the Deathly Hallows

The reason I bring up this quote, is because wands are the most important tool to do magic. I do believe using this quote will help you in seeking your answer.

This quote I do believe is by Hermione, and characters themselves could potentially say incorrect statements. Nonetheless, the quote was still written by Joanne Rowling. Therefore we must take it into consideration as it is cannon.

The reason that wands are only as powerful as the user is because of intelligence. You need to know precise wand movements and incantations. You need to be concentrated, and clearly think of what magic you are doing.

There was a lot more to magic, as Harry quickly found out, than waving your wand and saying a few funny words

For example, the Elder Wand semi-cancels out this quote[The first quote]. The Elder Wand for example may just enhance the users powers. An adult is most likely to be superior than a child of the age of fifteen. And you can't expect a younger child to do magic better than a very intelligent adult. You need to learn it.

Overall, yes, knowledge, experience, intelligence, concentration at the moment and innate ability are all very key factors. However, I do believe the power is all in the wizard, thus intelligence is the most important.