In "A Wrinkle in Time," a science fiction novel by Madeleine L'Engle, "IT" refers to a malevolent entity that represents conformity, control, and the suppression of individuality. IT is depicted as a vast, disembodied brain that exerts influence over others, particularly in the planet Camazotz, where it enforces a rigid adherence to sameness and eliminates free will. People are absorbed into IT’s collective consciousness, losing their personal identities and autonomy.
IT is considered evil because it embodies the threats of dictatorship, oppression, and the loss of individuality. The novel contrasts the dark conformity of IT with the importance of love, free will, and diversity. Characters like Meg Murry, her brother Charles Wallace, and their friend Calvin O'Keefe strive to resist IT's influence and ultimately learn that love and individuality are powerful forces against such evil. Through their journey, L'Engle explores themes of good versus evil, the importance of personal connection, and the strength found in diversity and love.