When we speak (be it words of comfort, or advice, or persuasion, etc.), sometimes we appeal to the words of someone whose authority on the subject can be agreed upon by both, the speaker and the listener. We do this knowingly or unknowingly, and examples range from as simple as, “my dad said it’s better if done this way…” to as complex as, “astronomers using NASA’s Hubble Space Telescope have discovered that the universe is expanding 5 percent to 9 percent faster than expected” (Ashley Morrow, NASA).