No single ideal body, many measurable types
Dürer rejects the idea that one canonical figure embodies beauty. He constructs many distinct body types, stout, slender, male, female, child, each expressed as fractions of total height, such as the head as one-eighth or one-seventh of the stature. Beauty is then judged as fitness and harmony within a type, and the artist learns it by measuring many living people rather than copying one perfect model.