Perception and Symmetry

Abstract

J.B. Leathes¹ wrote an eloquent paper entitled “Function and Design,” in 1926, in which he predicted, incredibly ahead of time, the possible role of nucleic acids in genetic transformation. He postulated that function implies ministration and structure implies adaptation to function. This may also be expressed as design. Both structure and design include symmetry. Our striving for the best functional design also means the appropriate choice of symmetry. In other words, symmetry has functionality. Nature demonstrates the relationship between symmetry and functionality in every instance. Animals and humans have bilateral symmetry evidently because upward motion is different from the downward motion and so is forward motion from backward motion, while motion is the same, or almost the same, left and right. Similarly, in the design of cars, trams, and airplanes, bilateral symmetry corresponds best to the kinds of motion these vehicles perform. Carrying this notion one step further, when we see a vehicle of bilateral symmetry, even when standing, we deduce the kind of motion it is used for. This is the unity of functionality, design, and perception.