The story of 左

left

左 depicts a hand with 工(a tool) next to it. Ancient Chinese thought that right hand is more important among two hands since it was stronger and more agile, while left hand was less important and was seen as an assistant of the right hand. Tool is an assistant of human beings so 工 is added to represent it is our left hand or the left. On the other hand, 左 also meant assistance or aid, but such meaning was then replaced by 佐.