There are three primary matters from which all the earthly things can be formed—land, air, and water. In terms of human composite, we are composed of body, spirit, and mind. The fluidity of the mind corresponds with the element water. Fish swimming in the water is the ego, the center of consciousness. In the sea of data compiled from thousands of years of human history, how does one discern the value of ideas? You infer to its echoing effect. "Ye shall know them by their fruits."