Ideals are fine, but here in the real world few of us measure up. Designers of desks, chairs, golf caddies, etc. know that designing for gods and goddesses is not only a waste of time, it’s bad business. Ergonomics—the science of how we physically interact with our environment—suggests it’s downright dangerous, or at least uncomfortable, to expect everyone to conform to a mathematical ideal when it comes to operating heavy machinery or kitchen appliances.

When much of our clothing and furniture was made to order, designs were often tailored to individuals’ proportions. When mass production took hold, designers embraced the average. Like Polykleitos, American designer Henry Dreyfuss created a model of human perfection based on mathematics. But while Polykleitos sought a mathematical sense of harmonious balance, Dreyfuss and his associates used math to calculate something less idealistic: the average Joe, and his female counterpart, the average Josephine.

Dreyfuss’ books, Designing for People (1955), The Measure of Man: Human Factors in Design (1967), and Humanscale 1/2/3 (1974) were the equivalent of Polykleitos’ Canon for the 20th century designer, and their impact is still felt (literally and figuratively) by all us consumers today.