Today, we meet the mother of invention, and she's not the lady we expected. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Simple pan balances go back to antiquity. Yet they're the basis for modern scales that make the most exacting measurements. An engineering colleague, Jim Casey, tells a remarkable thing about this important practical device. It seems that its inventors did not care a fig about weights and measures. They were trying to express the concept of balance, and that concept is really quite subtle. 

Think about blind-folded Lady Justice. She holds the law in one hand and the scales of judgment in the other. She shows us the scales -- the balance -- in quite abstract terms. Good and evil weigh against each other, not in kilograms or ounces, but in the common wisdom of society. 

That theme is found in the ancient Egyptian Book of the Dead, where souls are weighed against a feather. A soul strikes its balance in life, and that balance is felt on the scales of judgment. In other societies, leaders weigh their bodies against the tribute of their people. 

It's a mistake to look at these transactions as weighing and measuring. The concept of balance reaches far beyond that. The scale originated as an expression of that concept. It was created in the laboratory of ritual observance. It found no role as an instrument of commerce and science until much later in human history. 

The same thing is true of so many older technologies. Long before power-generating windmills arose in the medieval world, Buddhist monks were using sails to spin their prayer wheels. It's hard for us to understand why the wind was used in this way, before it was used to grind grain. But then we learn that ancients in every land saw the wind as the Breath of God and as a manifestation of the human soul. In that context we can better see how ritual came before, and led to, the windmill. 

There's no end to examples like this. The great structures of the ancient world weren't built to satisfy functional ends. No one ever lived in the colossal Egyptian burial constructions. They were born of ritual, and so too were the great Gothic cathedrals of the 13th century. 

Or consider the inverse of this: For thousands of years, Chinese pharmacologists have done enormously complex development of herbal cures. But, when they describe them, they use the language of metaphor. When, for example, they extracted estrogen millennia ago, the named it, the autumn mineral.

Technology and metaphor thus travel a two-way street. We begin to understand that when we realize that invention flows from something much more abstract than a wish to fulfill practical needs. The people who've actually created the great material artifacts of our world have been propelled by far deeper forces. They've been driven by the need to express a primal understanding that quite outreaches objective explanation. 

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

A. Seidenberg and J. Casey, The Ritual Origin of the Balance. Archive for History of Exact Sciences, Vol. 23, 1980, pp. 179 226.

This is a greatly revised version of Episode 232.

Detail from Albrecht Dürer's copperplate engraving Melencolia. This image is filled with metaphorical imagery, including a pan balance just to the left of, and above, the head of the melancholic angel.