Spontaneity is at the heart of cursive script, caoshu, reflecting the calligrapher’s ability to capture the fleeting moment and to express their thoughts and emotions in real time, without the constraints of careful planning. This essay will delve into this essential characteristic, exploring how spontaneity is both a technical element and a philosophical ideal within caoshu. We will begin by exploring the techniques that allow calligraphers to achieve a sense of spontaneity, focusing on the fluid movements of the brush and the continuous nature of the strokes. This emphasis on the flow of the brush underscores the spontaneous nature of the script.