Communication of Motion
Physical science is concerned only with mechanics. Therefore, it can be said that, in a collision, action and reaction are always opposite and equal. Such actions and forces, though, are only mathematical hypotheses. We only really know that the striking body loses motion and the struck body gains motion. We do not know if the motion is communicated from one body to another or if the motion is destroyed in the striker and is created in the struck. In the true nature of things, all bodies are passive. The truly active cause of motion is metaphysical and not the concern of physical science.
Read more about this topic: De Motu (Berkeley's Essay)
Famous quotes containing the word motion:
“As I walked on the glacis I heard the sound of a bagpipe from the soldiers’ dwellings in the rock, and was further soothed and affected by the sight of a soldier’s cat walking up a cleated plank in a high loophole designed for mus-catry, as serene as Wisdom herself, and with a gracefully waving motion of her tail, as if her ways were ways of pleasantness and all her paths were peace.”
—Henry David Thoreau (1817–1862)