One might call habit a moral friction: something that prevents the mind from gliding over things but connects it with them and makes it hard for it to free itself from them. ↗
They're keeping friction going between people from the East and the West. One thing we all got in common is your color, which is Black and Latino, which is our family. ↗
But heat can also be produced by the friction of liquids, in which there could be no question of changes in structure, or of the liberation of latent heat. ↗
Heat can also be produced by the impact of imperfectly elastic bodies as well as by friction. This is the case, for instance, when we produce fire by striking flint against steel, or when an iron bar is worked for some time by powerful blows of the hammer. ↗
Change means movement. Movement means friction. Only in the frictionless vacuum of a nonexistent abstract world can movement or change occur without that abrasive friction of conflict. ↗