John Calvin
Reformers such as Jan Hus and Martin Luther are seen as original thinkers, who started a movement. Calvin was a great logician. He organized a movement but dif not start as much  doctrine. He knew the writings of the early Church Fathers and the great medieval schoolmen very well. Earlier Reformers also influenced him. Calvin did not disagree with all of the scholastics of the Middle Ages, but he used them and adapted their thoughts according to his understanding of the Bible.