Slytherin



Slytherin is one of the four Houses at Hogwarts School of Witchcraft and Wizardry, and is traditionally home to students who exhibit such traits as cunning, resourcefulness and ambition. Its emblematic animal is the snake and its colours are green and silver. Founded by Salazar Slytherin, the house is composed mostly of pure-blood students, due to its founder's mistrust of Muggle-born witches and wizards. Slytherin house has a negative reputation, with many claiming that it is the source of most Dark Wizards in Britain, notably Tom Marvolo Riddle, a.k.a. Lord Voldemort, as well as many of his Death Eaters (followers). It has a traditional rivalry with Gryffindor. The great wizard Merlin was in Slytherin.

Slytherin corresponds roughly with the element of water.

Personality
Slytherins tend to be ambitious, shrewd, cunning, strong leaders, and achievement-oriented. They also have highly developed senses of self-preservation. This means that Slytherins tend to hesitate before acting, so as to weigh all possible outcomes before deciding exactly what should be done.

According to Albus Dumbledore, the qualities which Salazar valued in the students he chose included cleverness, resourcefulness, determination, and "a certain disregard for the rules." Dumbledore noted that all of these were qualities possessed by Harry Potter, who was in Gryffindor.

Reputation
It's said that all Dark Wizards were in Slytherin, though how many were from this house before Tom Marvolo Riddle began recruiting Death Eaters there is unstated. As Slytherin was his own House, it was certainly most easy for him to recruit there.

It might also be possible (though unlikely) that the Sorting Hat simply sorts anyone with ill intentions into Slytherin, regardless of whether they possess cunning and ambition. Vincent Crabbe and Gregory Goylewere both incredibly stupid and did not have that clever, cunning mind, but still sorted into Slytherin.

However, it must be noted that Slytherins who oppose use of the Dark Arts and discrimination based on blood purity do exist, such as Horace Slughorn and Andromeda Tonks; the latter was related to many different Dark wizards and witches (most notably her sister Bellatrix Lestrange, her brother-in-law Lucius Malfoy, and her nephew Draco Malfoy), but chose to forsake the loyalty to her family in marrying the Muggle-born Ted Tonks. Also, the allegiance of Severus Snape was found to be ultimately towards Albus Dumbledore, serving as a triple agent for the Order of the Phoenix. Furthermore, there have been Dark wizards from other houses; Peter Pettigrew, who betrayed James and Lily Potter to Voldemort, was a Gryffindor.

Cunning and ambition are easily turned towards ill purposes, but are not inherently negative; furthermore, daring, intelligence, and loyalty can as easily become negative. A reason Slytherins may be thought less of by people is perhaps because many of them seem to value their own lives more than the lives of others. When Harry was trying to run away, because he was afraid that his presence was putting his friends in danger, Phineas Nigellus saw him and said, "We Slytherins are brave, yes, but not stupid. For instance, when given the choice, we will always choose to save our own necks." There are exceptions to this rule however, such as Snape, who Harry said was a "Slytherin and...probably the bravest man I ever knew" and Regulus Black, who gave his life in an attempt to destroy one of the Horcruxes of Lord Voldemort.

The truth is that while most Dark wizards are Slytherins, most Slytherins are not Dark, and smaller groups of Voldemort's supporters are aligned with other Houses. During the Battle of Hogwarts, while all of the Slytherin students left the school before the fighting started, several of them did return with the Hogsmeade reinforcements to join the fight against Voldemort and his Death Eaters; although whilst in the Shrieking Shack, Voldemort commented that many had come to join his forces. Furthermore, it should be noted that the acting head at the time ordered the entire house to leave due to a single Slytherin student suggesting the student body hand Harry Potter to Voldemort.