He who knows nothing is closer to the truth than he whose mind is filled with falsehoods and errors. -- Thomas Jefferson"How do you know that?" Unless we are teachers in a classroom, or students in a philosophy seminar, we tend to raise that question only when confronted with a statement we find unfamiliar or uncomfortable. Just posing the annoying question risks being taken as challenging the good sense or honesty of the claimant.
So it is that many us stumble through life sticking with the familiar and comfortable beliefs we've had passed down to us, even though, upon reflection, we know that what people believe, or not, is not a measure of truth or falsity. How many times throughout history have people been called to sacrifice dearly for some Faith in an unexamined "Truth"? (What "truths" have been served by setting off bombs in civilian marketplaces and schools?)
Let's relax and consider. Suppose we wanted to know why the sun rises in the East and sets in the West. As we walk down the street we see coming toward us some familiar faces: three deeply educated men, Lorenz, Maurice and Curlius, believed by many to comprise the Wisdom of the Ages. We stop, greet them and ask, "Why is it that the sun rises in the East and sets in the West?"
They answer as follows:
Laurence, a scholar of ancient religions: 'Tis because Phoebus, the Sun, rises in his golden chariot in the East, drives across the sky to the West and then spends the night traveling underground to get back East to repeat the cycle."
Maurice, Ptolemaic scholar: Who believes that anymore? Actually, it is because the Earth, as center of the Universe, is circled by the Sun. What we call night is our period in shadow. The Sun's visible arc begins for us in the East and travels to our West.
Laurence interjects: Well, Maurice, I disbelieve your story. So there!
Curlius, erstwhile Copernican companion, declares: You may well believe your falsehoods, but the truth is that the Earth travels around the sun, spinning counterclockwise on an axis somewhat perpendicular to its orbit. So there!
Laurence and Maurice, both: Utter nonsense!
This interchange illustrates some principles we come to know at an early age, even though many fail to put them into practice in the direst of circumstances.
That some people believe something does not mean it is knowledge.
That some people disbelieve something does not mean it is not knowledge.
Our continuing controversies over evolution or global warming, illustrate these principles.
(However, were we to put the annoying question to our three sages, they, being deeply educated would likely be able to produce justifications for believing their respective claims to be true, as well as for rejecting counterclaims as untrue. So much for Plato's definition of Truth as justified, true* belief!)
But this goes way beyond the concerns of classrooms and philosophy seminars. What actions might have been forestalled, what decisions reconsidered, what bodies left unbroken, what lives saved, had the annoying question, "How do you know that?" been seriously considered at the appropriate times in the long, sad history of this planet?
For references and to examine these issues further, see Questionable Assumptions in Social Decision Making
*The truth condition is not practically separable from the justification condition. (See The Truth Condition)