Theories of Motion

The Greek “dunamis,” from which we get words like “dynamic,” can be read or translated several different ways, and each interpretation brings with it a world-view. At one end, we can translate it as the physical property of “potentiality.” This ignores, however, much of what Aristotle or another Greek would have meant by the word. They would have tied our material interpretation to other, metaphysical and immaterial meanings, ultimately, perhaps, including a concept of “divine power” and the force of a “daimon,” a deity inferior to the highest deity or deities.

If we ask today why a ball that we throw through the air continues to move after it has left our hand, we discuss mass, force, acceleration, momentum, and gravity, each of which can be measured, if not (yet) thoroughly understood.

But the dunamis, because it is immaterial, cannot be measured. Hence, we have learned over the past centuries to redefine it, to shape it into a concept (potential energy) that can be measured, and to ignore other meanings that it may have.

Further, ignoring these other meanings, relegating them to the qualitative sphere that we have gradually come to see as derivative of a more quantitative engagement with the world, we have come to disbelieve in their existence, to see their existence as superstition.

But this disbelief consists of a series of assumptions that put us in an illogical, if apparently reasonable, position. We may say that we have no need of an immaterial concept of the dunamis, that we find it extraneous to what we want to know and do, but we simply cannot pass judgment on its existence or non-existence. Without quite acknowledging it, we have allowed theory to become fact.

We throw a ball and it travels through the air. The ball weighs, say, 5.25 ounces and has a circumference of 9.25 inches. It’s covered in white horsehide and stitched with thick red threads. It spins and generates air pressure differentials that cause its trajectory to curve. The “force of gravity” (which we can measure but cannot yet comprehend or explain) draws it and the earth together. It drops past the batter’s knees, a called strike three. And there may—or may not—be a lower deity, a daimon, one of the dunamoi, guiding it along its way. We just don’t know.

Am I actually suggesting that I believe in immaterial beings of motion? I don’t believe but I also don’t disbelieve in them. But I acknowledge that my belief in physics does not contradict a belief in a qualitative understanding of motion and even of beings of motion, the dunamoi.