Pleasure derives from that tension that comes in the scraping of surfaces against one another. The violent confrontation of surfaces tears small bits from each and deposits them in the minor pits and cracks of the other—even as these flaws are what produces the friction. They annihilate each other in the rough of their stroke. A polish is not a velvet caress, but a gritted swipe at the flesh of the other. It is greedy to incorporate the thorns and spines of its beloved in the furrows of its own offenses. Planted there, they grow down into the muscle and bone like new tongues of dendritic nerve, touching tender cores of feeling, and spreading at the surface a soft mold of fine furred rind.