Facts Are Often Theory-Dependent

Suppose you and your astronomer-friend are camping along the Appalachian Trail in the Blue Ridge Mountains of Virginia. As you awake at dawn from the first sound of stirring wildlife, you sleepily notice a rosy, picturesque sunrise.[1] With a bit of alarm you anticipate rain showers and a muddy hike ahead. As you rouse your friend, you comment, "Look at that sunrise; we're in for trouble." Assume, moreover, your friend dimly responds with a slow yawn, "I see the sun, but there is no sunrise today or, for that matter, any day."

What do you say? Is your friend's statement sensible? Presumably his eyesight is just as good as yours, and evidently he is looking where you are looking. Yet, your friend is apparently claiming he does not see what you see. You see the sunrise; he apparently is stating he does not. Now, is there any chance you could be mistaken? Let's pause just a moment and see if this exchange makes any sense.

You do see the sun rising today, and you have seen it rise countless times in the past. Your friend, however claims not only is there no sunrise today, but there has never been a sunrise. Is this disagreement a misunderstanding over the meaning of words, a misunderstanding due to personal feelings, or a misunderstanding concerning relevant facts at hand? Also, assuming we know what kind of dispute it is, how should we go about resolving it?

Sunrise in Smoky Mountains, Clingman's Dome, NC

You would have to be a gentle person to think this far without suspecting, perhaps in some exasperation, that your friend is half-asleep, does not know what he is saying, or has some other kind of brain-trouble. However, in order to make this disagreement a bit more interesting, let us further suppose that your friend is beginning to warm up to the strange looks you are giving him and proposes a bet. If you can convince him that the sun is rising after all, he will prepare all meals and wash all utensils for the remainder of the camping trip; if not, then you will prepare all the remaining meals and wash the utensils.

Would you take the bet? Only a cursory look at the remains of the previous night's repast might be sufficient to convince you to accept the wager. After all, everybody knows the sun rises every morning whether we see it or not.[2] It is difficult to resist the payoff; you accept the bet and begin thinking about proving your case.

On the one hand, how do you go about proving such an obvious and well-known truism? If you proceed somewhat systematically, you might first begin by getting clear and obtaining agreement about the meaning of any key terms in the dispute. Most important, what does "sunrise" mean? Once the significant terms are defined, then facts can be sought to verify the hypothesis. Let us suppose your friend will reply something along the lines of "sunrise" means "the usual daily movement above the eastern horizon of the star which is the center of our solar system." Second, you might seek to show him that the facts correspond exactly to his definition. That is, while eagerly anticipating his preparing of breakfast, you simply point out the observation that the sun is rising above the horizon, as expected. Finally, you could note that no undue feelings or attitudes have shaped your position on this issue and cloud the judgments and observations of either you or your friend, the other disputant.

On the other hand—let's say you are beginning to be hungry—no telling how long your dim-witted friend will hold out before admitting that he actually does see the sun rising in the sky. O.K., the sun does move rather slowly. Why not put the burden of proof on him? Let him prove that the sun is not rising. We often take the approach of assuming we are right if our beliefs cannot be disproved.[3] Thus, here in the Blue Ridge Mountains you put the question directly to your friend. "What could you possibly mean by saying, 'The sun doesn't rise and isn't rising right now'? Just look!"

Your friend sleepily replies, "Do Kepler and Tycho see the same thing in the east as dawn?"[4]

Alas, you probably remember that Tycho Brahe, as well as most other folks at the time, thought that the earth was the center of the heavens. Kepler was one of the first persons to regard the earth as revolving around the sun. If the earth moves around the sun, then it appears as though your friend is correct. The sun does not really rise, the earth turns. Even worse, he's apparently right when he said the sun has never risen.

Doesn't it seem that by now our culture would have this simple fact entrenched in our ordinary language? We do see the sun rise; we do believe the sun rises. Aren't these facts? Accordingly, both you and your friend do not really have the same visual experience since your conceptual interpretation of what you see differs from what he sees. Even though the patterns of light and color are the similar for you and him, what you experience is largely dependent on the theoretical perspective from which you view the event. Just as we cannot know a foreign language only by listening, so also we cannot know the sun rises only by seeing. It is not at all unusual for two skilled investigators to disagree about their observations, if each is interpreting the the data or "facts of the case" according to different conceptual frameworks.[5] Just as your mind-set affects what you see, so also your awareness of other mental perspectives can affect what you know. The learning of new perspectives is what, in large measure, philosophy is all about.

Solar System, BNSC HMG



"Red in the morning is a sailor's sure warning."


Note the argumentum ad populum.


Note how this presumption, as well as the friend's original bet could be viewed as an example of an ad ignorantiam fallacy. If a statement or a point of view cannot be proved beyond a shadow of doubt, then that statement or point of view cannot be known to be mistaken. The ad ignorantiam fallacy occurs whenever it is asserted that if no proof of a statement or argument exists, then that statement or argument is incorrect. The error in reasoning is seen when we realize nothing can be validly concluded from the fact that if you can't prove something right now, then the opposite view must be true.


For a detailed analysis of this question, see Norwood Russell Hanson's Patterns of Discovery, New York: Cambridge University Press, 1958, 5.


Frederick Grinnell. The Scientific Attitude. Boulder, CO: Westview Press, 1978, 15.