<human>:  Where does the term ‘illusion’ come from in the theory of ‘Illusionism’?
<bot>: The term illusion comes from the Latin word illusio, which means deception. Illusionism is the branch of psychology that studies the psychological effects of deception. The theory of illusionism suggests that people are not always aware of their own beliefs, and that they can be tricked into believing things that are not true.