Kant thinks that the laugh comes from the passion which suddenly transforms from the intense expectation to nihilism,which is the subject s appreciation to "illusion",namely,which is the relaxation of body that is caused by the loss that the subject pursues understanding.

Based on the research of Leibniz-Wolf’s philosophical system and the analysis of category deduction,Kant divided transcendental illusions into three kinds,namely illusion of soul from psychological idea,illusion of world from cosmological idea and illusion of God from theological idea.

The transcendental illusion is the main notion of the transcendental dialectic in Kant\'s Critique of Pure Reason(CPR).

Illusion because of affection,Expressing affection by affection On the Synthetiall relationship between “affection” and :illusion in 《A Dream of Red Mansion》;