The reason we know this sign is true is because the expression arrived as a result of verifiable observation on the part of Mr. DeMan. The “Why?” of it can be easily explained to anyone who knows the difference between facts and metaphors.
- Metaphors probably arrived in human consciousness long before facts became part of arguments between (hopefully) friends. Figurative language gets used to paint images in the minds of others, whether to enhance understanding or to mislead. Metaphors about reality only require trusting the instructor for acceptance as factual. The ease of using only words and occasional graphics to generate mental images makes indoctrination of young, innocent subjects easy to accomplish.
- Facts are not so easy to gain or communicate without tools to demonstrate them. Whether about actual events or existences, or conditions of reality, facts require objective evidence to corroborate them. Due to their often covert nature, facts stay hidden from the innocent and uncurious. Complex facts require elaborate preparation, often at great expense, for demonstration, which appears to give hoaxers and naysayers an upper hand at thwarting acceptance.
Legitimate expectations would not demand each interested person to duplicate each set of tests just for the privilege of talking about science. Scientists have overcome some reluctance by employing rules along with the scientific method to encourage trust and, even more, to prevent mistakes by preventing opinions and emotion-driven input from entering the mix. Despite overzealous marketing from some science magazines, scientific facts have become the most trustworthy kind of information—once you have trashed all the imposters who can only wish they deserve the title, but do not hesitate to contribute to the undeserved distrust of science.