A magician has two people concealed in a long wooden box, one whose head and arms stick out of the box, and the other whose legs stick out. When the magician saws between the two people the audience thinks the magician is sawing one person in half. This trick is based primarily on the Gestalt principle of

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The trick relies on the Gestalt principle of closure, where the audience perceives the disjointed parts (head and arms of one person, legs of another) as a complete single form (a whole person) because their minds fill in the missing parts, creating a unified whole from the separate elements.

A Magician Has Two People Concealed in a Long Wooden