Salazar Slytherin is often painted as the black sheep of Hogwarts' Founders, and his house is well known for producing some of the world's most villainous dark wizards. However, history is never as simple as appears, and there are many things to consider past surface appearances.

One of the most critical points being the period he lived.

Most of what follows is speculation, though backed by historical norms of the Founder era as well as contextual evidence from the books. This is an edited version of a college paper I wrote for a Fantasy class in college, and this seemed like a good place to share, and hopefully invite discussion on a topic I haven't seen often explored within fandom space.

And I am very aware of what J.K. Rowling said after the series ended. I am purposefully disregarding anything not in core canon. Because I think it's far less interesting to paint Salazar as a simple villain and Godric as a pure hero who could do not wrong, and yes I am still feeling petty over it years later.

           "They built this castle together, far from prying Muggle eyes, for it was an age when magic was feared by common people, and witches and wizards suffered much persecution." (Professor Binns, Chamber of Secrets, pg. 150)

            The truth of the matter is that we don't know the "true" nature of Salazar Slytherin, but by the quote above we can understand the situation that he and others found themselves in. Hogwarts was canonically founded somewhere around 990 A.D. when Christians were finally taking hold of Scandinavia. Thus, towards the end of the Dark Ages, or else the Early Medieval Period, in which Europe was famous for its intolerance of non-Christendom. This included the teachings of Ancient Rome, Greece, any Eastern countries, and much that was considered abnormal or unnatural. The latter of which magic would fall into firmly. People were publicly defamed and sometimes even killed for nonconformity. Put in a group of people who not only endorse ideas of magic, but are magical beings themselves?  What would the founders do about this to protect the school? That was where I believe the first disagreements between Salazar and the others began.

            Considering his house's traits, Salazar Slytherin would have reasonably believed that cunning and resourcefulness would be key tactics should this tension between the muggles and the wizarding world come to blows. Those with ambition sought ways to rise above opposing forces, and self-preservation meant they would go far to achieve the ends necessary for survival. Godric Gryffindor wanted the bravest admitted. He would have thought that the most dauntless of students would provide a ready security, should Hogwarts defenses be compromised. Rowena Ravenclaw valued the tactical advantage intelligence would bring. Should magic be the weapon of protection, a well thought out practical plan would be essential. Helga Hufflepuff would have had a different view. Admit those loyal to Hogwarts who showed themselves as hard-working, and security would not be a problem. Her students would protect the secret of Hogwarts for the sake of loyalty, rather than fear. 

    Four different views, one goal: survival.

            However, add in the factor of Muggleborn witches and wizards, and an extra layer of problems and complications would arise. In days where magic and wizardry were thought to come from the devil, the notion of having a wizard or witch in the family would not be welcomed. Even if magic was accepted by parents out of love, what about their neighbors? What about the child? Would a young wizard, born from Muggle parents who loathe magic, so readily acclimate? Would it be possible that one of these children could be forced into revealing the secrets of the Wizarding World? Would it be possible that they all could be put at risk by accepting Muggleborn students? That is where Slytherin began to diverge and where his reputation for prejudice could be historically tied. He may have seen these all as possibilities, and his value on self-preservation would lead him to action the others would not agree with.

            Gryffindor is well known for bravery, so it would be unlikely that he feared the damage of a handful of Muggle villagers to a school full of wizards. Ravenclaw was wise and would argue that more knowledge, not less, was the way to peace. Teaching Muggleborns would be an excellent way to show that there was nothing inherently evil about their gifts. Hufflepuff would want to "take the lot." There is no student she would turn away, regardless of parentage. Magic was for everyone with the gift for it, and everyone should have equal opportunity to learn.

            Slytherin might concede that the other Founders brought up good points, but none of it would matter if they died. Perhaps they could defend themselves against a handful of Muggles, but what of an army? What would be the cost even if they managed to repel attacks? Canonically muggles vastly outnumber those of magical birth. Would it not be more strategically sound to leave Muggleborns out of the discussion, at least until the world became a safer place for witches and wizards? Then they could both keep themselves safe and focus on their shared goal: teaching students. Not trying to change the nature of Muggle and Wizard relations. This viewpoint is far from the blind hatred characters, and many fans alike, attribute to Salazar, but far more likely considering a key passage in the Chamber of Secrets.

            "He disliked taking students of Muggle parentage, believing them to be untrustworthy." (Professor Binns, Chamber of Secrets, pg. 151)

            Untrustworthy, not lesser or undesirable. This reinforces the point that it was more likely for his exclusion to result from fear than blind hate. Even with protections around Hogwarts, if someone who knew the way led others, all the hard work put into keeping their secret would be lost. Then we have the Chamber of Secrets, which is often cited as evidence of malicious intent. No sane man would lock a Basilisk in a school full of children. However, what if Salazar Slytherin had planned it as a panic room? It would be one that only he could open should the school eventually come under attack. This makes sense and would be no different from Dumbledore putting a Cerberus in the school to guard the Philosopher's stone. In fact, it would be more justified in this case. It would not protect one item, but the entire school and every student inside.

            He found a creature that only he could control, a monster that could annihilate an entire army just by looking at them, and that could also get around parts of the castle from inside the walls. Over that one-thousand years, the Chamber became a legend, and its original purpose could have easily been perverted.

            Legend says Salazar put a monster in the school, sealed it away, and told everyone that his decedent would be back to kill the Muggleborns at some unspecified time in the future. Salazar never 'unleashed the horror within,' even when he could have before leaving the school. Instead, not only are the Muggleborn students now afraid to incur the 'wrath of Slytherin', but should the other founders fail at protecting the school, Salazar already had a worst-case solution in place. Though even living longer than Muggles, it is a reasonably safe assumption that when Salazar Slytherin stated that his 'own true heir' would return, he probably was not thinking much further into the future than his great-grandson. If nothing ever happened, then the Basilisk would not get out, and it would not matter.

            Another thing to consider about his character is that Salazar was Godric's best friend. So, if Salazar were a dark wizard, why would the other founders have let him into their circle? Even if he were a brilliant actor, one of the other three would have seen through it with how competent they were said to be. Until their falling out, by all evidence they were all four close. He left the school of his own accord in peace and without violence. That last part is stated quite clearly by the Sorting hat, who would have been there at the time.

"And at last there came a morning.

When old Slytherin departed.

And though the fighting then died out.

He left us quite downhearted."

(Sorting hat, Order of the Phoenix, pg. 206)

            So it seems they were sad at his leaving, which leaves reason to suspect that their friendship would still be intact.

            As stated in my lecture, The History of Modern Fantasy:

            "Almost everything written before the Age of Enlightenment was based in myth, legend, or superstitious belief."

            Skip ahead one thousand years, and even less is known about Slytherin. Most wizards and witches know only that his house has produced several dark wizards and has a history of prejudice. Considering that the Wizarding World, as far as we know, never even had an Age of Enlightenment wouldn't they be even worse than we are when it comes to twisting legends and fearing myths? Hagrid, one of the most kindhearted characters, claimed that "There's not a single witch or wizard who went bad who wasn't in Slytherin." However, Merlin was himself a direct handpicked pupil of Slytherin, and as we learned later on, Peter Pettigrew went bad and was a Gryffindor.

             With the name of Slytherin House tainted by so many dark wizards, it stands to reason that the founder would be as well. Despite all the evidence that can be collected to contradict this belief. Slytherin, who disagreed with the other founders, all known to be good, would then be painted as evil. Then, enter Tom Riddle. A Parselmouth with delusions of grandeur. When the Basilisk attacked students, it was doing so at Tom's behest. The Basilisk was controlled, and when the voice commanding it told it to kill Muggleborns, it obeyed. If Riddle had told the Basilisk to kill only Muggles or giants or people named Steve, the Basilisk would have done that as well. Future racists and pureblooded elitists will take and twist Salazar's words, as young Tom had, having heard only the story that has been passed down for a thousand years. They would use this same "caution" to justify their want for genocide.

            Except they were no longer worried about safety. Those such as the Death Eaters only wanted to keep themselves "pure." No longer were they defending themselves against a threat as a people who were faced with prejudice themselves, but instead had become a threat to anyone they did not see as equal. Salazar was not wholly right in what he did, but unlike the Pure Blood supremacists that came later, there was no evidence he ever harmed a single person. In fact, Salazar himself was part of a persecuted class and likely would have known those who had been harmed at the hands of prejudice, if not directly impacted by it himself.

            Salazar would have had no way of knowing how deeply ingrained the bigotry towards muggleborns would become and certainly had no way of predicting the likes of Tom Riddle. The Chamber of Secrets might never have been found otherwise and would have persisted only as legend.

            Was Salazar evil? Maybe misguided, but the evidence suggests events were not nearly as black and white. Maybe he is not purely good, but the historical context suggests more than malice, and he was still one of the Founders. Salazar Slytherin was Merlin's mentor and best friend of Godric, Rowena, and Helga. Could he have turned "evil" from his fear? We cannot know for sure, but he is a compelling character vastly more nuanced than commonly portrayed.

So goes my theory on Salazar Slytherin. I would love to hear why anyone may agree or disagree. This is also really wanting to make me continue my Founders story, which I might do. Because no matter how much time goes on the simplicity their backstory is portrayed with still bugs me, and I doubt that will end any time soon.