The shell bone script of character Negotiate is
The top is top part of character Say (Post 158)
which means tongue, the organ for speaking.
The bottom is character Cave (Post 44), the residence of human in the ancient time.
The cave could be a place for people gathering to negotiate important things, what was the most important thing in more than 3500+ years ago: foods. People didn't have enough foods most of the time, they shared the foods to survive. Therefore, they negotiated how to divide the foods they got either from planting or hunting or collecting. Most of time, it is distributed equally, that means total foods (weight) divided by number of people, the quotient is the result of the operation. The original meaning of the character was Quotient, and it still has the meaning now.
People used their tongue to negotiate how to distribute the foods or substances.
Why did the ancient people put the tongue outside of cave? They might have wanted to emphasize the situation: many people or all people did use tongue (to speak) and very loud, the sounds could be heard outside the cave. If put the tongue inside, it may be thought one person in speaking, and the sounds are weak.
The bronze script of character Negotiate is
The top is tongue, the cave, and the mouth (口）inside the cave, which may mean that there are many mouths in the cave speak to discuss how to distribute.
Small seal script of character Negotiate is
Similar to bronze script in structure, but the lines are more symmetrical and smoother.
The clerical script of character Negotiate is
Similar to small seal script with one line eliminated: the U shape line in small seal script disappeared in clerical script.
The song typeface of character Negotiate is
Similar to clerical script.
