In prehistoric era, while humans have always had propensity to solve their differences by fighting, they have too recognized benefits of settling matters peacefully by flipping a coin/ some other way. With pursuit for alternatives to violence gave introduction to originator of alternative dispute resolution. The English trial is adversarial. That is to say it takes the form of a sort of battle between two (supposedly) equal parties.
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The origins of the system go way back into feudal times and the very local and decentralized