Cadwallader Colden played many roles during his long life--philosopher, historian, naturalist, physicist, and statesman. His surviving papers hint that he would have preferred, above all, to be remembered for his discoveries in theoretical physics, but his work in that field, more than in any other, reveals his shortcomings. While the importance he attached to the powers of observation allowed him to excel as a naturalist and to write an original and influential history of the Iroquois, his overemphasis on the observable--and paradoxical neglect of the experimental--led him into error. Colden also applied his physical principles to human thought. Though his ideas have long been rejected as bad physics, they remain intriguing philosophy.

Colden was born in Ireland on 7 February 1688 and raised in Berwickshire, Scotland, where his father, Alexander Colden, ministered to the Presbyterian congregation at Duns. His mother's name is unknown. He attended the University of Edinburgh, where...