In play, we have two forms of the will to power : the form which consists in learning to do things, and the form which consists in fantasy. Just as the balked adult may indulge in day-dreams that have a sexual significance, so the normal child indulges in pretences that have a power-significance. He likes to be a giant, or a lion, or a train .
Source: On Education, especially in early childhood, 1926, Pt. 2： Education of character, chap. 5: Play and fancy
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