Rev. Parris came upon a group of girls dancing in the woods late at night. One of the girls was his niece Abigail; another, his own daughter Betty. When he jumped into the scene, he frightened the girls so much Betty went into shock. Parris, the Minister of the church in Salem and (supposedly) a respected leader of the community, needs to find out what the girls were doing. Since Betty is unresponsive, Parris turns to Abigail.
He observed a kettle of soup, and his slave Tituba singing songs and waving her arms over a fire. Tituba being a slave from Barbados, Parris is aware that she was not always a good Christian and might have special powers that were in use in the woods. He is reluctant to label it witchcraft, mostly because he is in denial that his own child would be involved in such a thing (his niece-- I don't think that would surprise him much).
Doing Witchy and conquering spirits