Other things that were used before toilet paper include: Hay, corncobs, sticks, stones, sand, moss, hemp, wool, husks, fruit peels, ferns, sponges, seashells, and broken pottery. 15. 70-75% of the world still doesnât use toilet paper because it is too expensive or there is not sufficient plumbing.
Propensity is defined as a natural tendency. An example of propensity is an inborn love for writing. pl. -Â·ties. 1  a natural inclination or tendency; bent.  Obs. favorable inclination; bias (for)
The main challenge facing propensity theories is to say exactly what propensity means. And then, of course, to show that propensity thus defined has the required properties. At present, unfortunately, none of the well-recognised accounts of propensity comes close to meeting this challenge.