A "truism" is a statement or principle that over time comes to be accepted as fact. If, at some point, proven data should arise that contradicts that accepted truth, then we are left with a "fallacy." But old truisms die-hard and many times those who challenge them are ridiculed.

For hundreds of years it was an accepted truth that the earth was the center of the universe and all the heavenly bodies rotated around it. Galileo, the scientist who invented the telescope, published his findings which proved that actually the earth revolved around the sun. The scientific community was so upset with his departure from accepted theories that they threatened to bring Galileo before the court on charges if he did not retract what they considered irresponsible statements.

Over the years, the art of hitting a baseball has developed its own list of truisms. (I understand that I'm releasing my findings at my peril).