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How can you ever know that you know anything, except perhaps in retrospect? For example, I know that the sun will rise tomorrow. Then, say the sun doesn't rise due to some strange astronomical phenomenon that no one knew about/had evidence for. Clearly, I did not know that the sun would rise, since it didn't in fact rise (knowledge has to be awareness of facts. However, if it is possible to be wrong about knowing something even when you have conclusive evidence, how can you ever know that you know such propositions to be true in circumstances such as these? What is the Objectivist position on this kind of issue?

Also, as a slightly different scenario, let's say I made the same claim, and the sun did in fact rise. Did that mean that I also knew that it was false that the sun would not rise the next day?

asked Nov 06 '10 at 03:54

ttime's gravatar image


The question asks: "What is the Objectivist position on this kind of issue?" -- referring to cases in which there is a change of context such that knowledge applicable in the old context is not entirely applicable in the expanded context. Objectivism regards all knowledge as contextual. Refer to the entries on "Knowledge" and "Context" in The Ayn Rand Lexicon for an initial introduction to the Objectivist view.

As for knowledge allowing one to predict the future in cases where the context hasn't changed, that is the problem of induction. A recently published book titled, The Logical Leap: Induction in Physics," by David Harriman, applies Objectivist principles to the problem of induction, although there is current controversy about how well the book does or does not accomplish its goal.

answered Nov 07 '10 at 01:36

Ideas%20for%20Life's gravatar image

Ideas for Life ♦

You know something when your idea corresponds to reality. You know reality unless you are unhealthy because you are an organism with sense-organs and a brain than responds causally to create knowledge. Prediction is a special case of knowledge. The reason the sun ever "comes up" is that the earth revolves on its axis in 24 hours, around a star. The stability of that system (the solar system) is something we know something about, and the sort of astronomical event that could alter the solar system is the sort of event we would notice coming. There are no grounds to create doubt about the stability of the solar system this week, so you know the sun will come up tomorrow. Doubt would be a case of ignorantium, of asking how one doesn't know something--asking how one doesn't know that something will occur that changes everything.

Knowledge is reliable because reality has identity. Identify something, and your knowledge is reliable because things are "constrained" by their identities. It is because the solar system is what it is that the sun will come up tomorrow. Prediction depends on warranted diction. So when we learn to say why a thing happens, we come to be in a position to say when it will or will not happen.

answered Nov 07 '10 at 13:54

Mindy%20Newton's gravatar image

Mindy Newton ♦

edited Nov 07 '10 at 16:28


Mindy, you can (and should) EDIT your content to make it as good as it can be. So you need only comment on your own answers in response to others' comments, to prompt their deletion for being moot/distracting. Or to let people who are subscribed to updates on a topic know that you've edited your answer so they might to return to enjoy your changes (and comments like this should be immediately deleted because they have already served their purpose and become distractions). Please see the Tips section in the FAQ.

(Nov 07 '10 at 14:55) Greg Perkins ♦♦ Greg%20Perkins's gravatar image

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Asked: Nov 06 '10 at 03:54

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Last updated: Nov 07 '10 at 16:28