he cause of both his inspiration and his downfall, Snape's beliefs frame his person and mark his life path. From an early desire to learn more about the Dark Arts to his sorting into Slytherin to his becoming a member of Voldemort's Death Eaters, Snape's life is set by the beliefs he holds.
ne of the defining constitutions of Hogwarts' Slytherin House is the belief in pure-blood superiority, a belief to which Snape, despite his heritage, subscribes. Slytherins, as their founding father Salazar Slytherin before them, take pride in pure-blood heritage. Those who are not pure-blood, such as Snape and Voldemort, keep their true blood status to themselves. To not be pure of blood is to a Slytherin to be unworthy.
The pure-blood privilege runs rampant in the magical world under many guises. On the extreme side there are those like Voldemort and his followers who are blatant and discriminating in their belief of mixed or "Mudblood" inferiority. But a more subtle meme feeds on the Witch and Wizard population: a lesser form of prejudice that speaks to a hidden animosity and privilege. To the least hostile degree we have Arthur Weasley, obsessed with Muggle technology, who can hardly believe that Muggles would have the capacity without magic to create the remarkable things that they do. More blatantly, there are those like Horace Slughorn:
‘Your mother was Muggle-born, of course. Couldn’t believe it when I found out. Thought she must have been pure-blood, she was so good. (…) You mustn’t think I’m prejudiced!’ he said. ‘No, no, no! Haven’t I just said your mother was one of my all-time favourite students?’
Chapter 4: Horace Slughorn
Harry Potter and the Half-Blood Prince
Here, Slughorn reveals the pure-blood superiority over magical powers among magic-users. His expectation is that those who are not pure-blood are not as powerful or gifted with magic. He attempts to atone for his slip-up by insisting he respects Harry's mother, Lily, who was a gifted witch with Muggle parents. But his atonement falls flat: clearly, he respects Lily in spite of her Muggle heritage. If Slughorn truly believed there was no difference on this respect between Muggle-borns and pure-bloods, not only would he not be shocked, he would not have even brought up the fact of differing birth.
In seeming contrast to this belief, Snape calls himself the "Half-Blood Prince", referring to his mixed parentage and his pure-blood mother's last name. Harry, upon discovering the "Half-Blood Prince"'s identity, decides that Snape had hidden his identity during his student days at Hogwarts to gain the approval of the budding Death Eater group there. (Ch.30, HBP) Snape would probably have admitted this to be true. Not only is having pure-blood a virtue to those in Slytherin House, the Death Eaters, with whom Snape associated even as a young student at Hogwarts, required all members to be pure of blood. The irony of its two most powerful wizards — Voldemort and Snape — being half-bloods should not be lost. But Snape, in taking on his secret identity, shows some pride in his true heritage as well. A brilliant wizard, Snape's hand-crafts spells become popular among the students at Hogwarts in his day, and are eventually even turned against Snape himself. (Ch.28, OotP) Generations later, Harry and Ron speak to the brilliant mind of the Half-Blood Prince. (Ch.12 & 25, HBP) Snape, through his secret identity, proves his genius does not rely on his blood status.
s a child obsessed with the Dark Arts, it only made sense that Snape would seek out others of a similar mold. His knowledge of the Dark Arts and arsenal of curses make him infamous at Hogwarts School of Witchcraft and Wizardry. (Ch.27, GoF) Snape is given the opportunity to join a group of Dark Arts-obsessed individuals; his knowledge of curses of a darker sort prove to make him the perfect candidate for Voldemort's Death Eaters.
Even when Lily's death provokes a switch of sides, Snape's respect for Death Eater values and Voldemort himself remains. Even at risk of loosing Lily's friendship, Snape continues to immerse himself in the Dark Arts and associate with the baddest apples of Hogwarts. (Ch.33, DH) When referring to Voldemort Snape tends to call him by the honorific "Dark Lord", which isn't missed by Harry Potter. (Ch.26, OotP) Although Snape isn't given time to respond to Harry's accusations, it should be clear that he uses the honorific out of fear and respect. Fear, for saying his name may invoke his attention, and the attention of one of the greatest Legilimens is not something one should go looking for. Respect, for despite his insanity and evilness, Voldemort is an accomplished leader, magic-user and visionary. If not for his love for Lily and her death, Snape would have happily remained in true alliance with Voldemort and his group.
nape held a lifelong appreciation for the Dark Arts. As a child, he comes into Hogwarts with an array of dark spells at his disposal, much to the estimation of of house-mates and the condemnation of the rest of his peers. As a student, his favourite class is Defence Against the Dark Arts, and as a professor he yearns for the opportunity to teach the course.
What Snape most pined for was the position of Defence Against the Dark Arts professor. His desire for the position was well-known throughout the school's population. (Ch.7, PS/SS; Ch.5, CoS; Ch.5 PoA) He even appears to display a special animosity towards all those who take on the position, as noted by Harry. (Ch.14, GoF) Throughout Harry's first year, Snape appears to treat Professor Quirrell so poorly that he can barely keep back his shivers in Snape's presence. (CS/SS) When, in his third year, Harry fears Snape is acting out against Lupin, he reveals to his favourite teacher the possibility that Snape is trying to take over his job. (Ch.8, PoA) In Harry's fourth year, Snape treats Moody with blatant dislike. (Ch.14, GoF) Snape resents the fact that others are chosen over him for the position.
Possibly the greatest happiness of Snape's life after Lily's death was his instatement in Harry's sixth year as Defence Against the Dark Arts teacher. When Dumbledore makes the announcement at the start of the year, Harry clearly sees how happy Snape is at finally having his wish fulfilled. (Ch.8, HBP) Snape is in his element as teacher of the Dark Arts-oriented class. As Harry relates, he redecorates the classroom with grotesque images of victims of the Dark Arts. (Ch.9, HBP) During one class, Snape exclaims in a voice that Harry notes as having a certain "loving caress" about it:
‘The Dark Arts,’ said Snape, ‘are many, varied, ever-changing and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before. You are fighting that which is unfixed, mutating, indestructible.’
Chapter 9: The Half-Blood Prince
Harry Potter and the Half-Blood Prince
Snape's reverence of the Dark Arts is obvious here. He is proud of the qualities the Dark Arts genre of magic sports, exuberant in relating these qualities to the students under his guidance. But, as Hermione of Harry later compares, Snape's thoughts on the importance of teaching the Dark Arts is not merely for their dubiously marvelous qualities, but for simply having a knowledge of them, in particular what they can do. Snape may believe that one cannot know fear until one knows the source of the fear.
The root of Snape's obsession with the Dark Arts is hard to pinpoint. Speculation can be drawn from his dreary home situation, his social status as an outcast, and his desire to be the best, to inspire awe and fear in others. Unfortunately for Snape, this last point works against him; according to Sirius, James, who had bullied Snape from the first, had only hated Snape more when he found out how appreciative of the Dark Arts Snape was. (Ch.29, OotP) Still, his yearning to learn more about the Dark Arts and his success in not only discovering knowledge but creating dark spells of his owns allows him to exercise his creativity and eventually lends him the respect he craves.