Answer :
This question is about "The crucible"
Answer:
Because Arthur Miller was showing how slavery is manipulative and incriminating.
Explanation:
Tituba is the slave of the Reverend Parris. She practices what the Puritans call "black magic" and recognizes that she is involved in witchcraft, but not before showing how white Puritans were hypocrites and just as bad as she is, showing what Reverend Parris (her "owner") ask her to do it.
When Miler wrote this scene he wanted not only to present the hypocrisy that was established among religious leaders, but also the manipulative character that slavery provided, in addition to showing the domination of whites over blacks.