In this way some systems of law have grown up.

They began by regulating procedure.

Each of two parties claimed something as his property, was ready to fight to maintain his right; but such contests might result in injustice, and were certainly injurious to the peace of the State.

In early Roman Law each party who claimed the object in dispute touched it with his spear, showing his readiness to fight for it; then some respected citizen--_vir pietate gravis_--stepped in, and each party, without fear that his refraining from fighting would expose him to future encroachments on his rights, could agree to abide by his decision.

As time goes on, what was merely the casual intervention of an arbitrator becomes an habitual rule, and eventually the fixed law of the land.