Straining to see the world through triangle-shaped lenses, Pythagoreans argued that in heredity too a triangular harmony was at work. The mother and the father were two independent sides and the child was the third—the biological hypotenuse to the parents’ two lines. And just as a triangle’s third side could arithmetically be derived from the two other sides using a strict mathematical formula, so was a child derived from the parents’ individual contributions: nature from father and nurture from mother.
