Final answer:
Milton referred to banning books as 'a kinde of massacre' because he believed it suppresses free thought and intellectual growth.
Step-by-step explanation:
In his writings, Milton referred to banning books as 'a kinde of massacre' because he believed that by banning books, society is essentially killing ideas and knowledge. He saw books as a means of preserving and spreading information, and believed that restricting access to books was akin to suppressing free thought and intellectual growth. Milton believed that a free and open exchange of ideas is essential for a healthy society, and viewed book banning as a form of intellectual violence.