Sunday, December 6, 2009

On Probability, AD 1491, and The Relation Between What We Know and What Is

I've on occasion run across an atheist who has argued that, while yes there is no proof that there is no God, it is the "more likely" conclusion that God does not exist.

The argument is an interesting one, but the problem is, it is based on assuming what we do not know in relation to what is.  If we assume we know 95% of everything that is, then there is a danger of assuming that the 5% we think we don't know is going to be more of the same.

Yet, if we don't know what is in that unknown portion, we have no idea whether what we don't know is 5% or 50% or 99.9% of what is.  Nor do we know what is in that unknown portion.  Perhaps it is the knowledge which will cure AIDS.  On the other hand it could be the knowledge that an AIDS cure is as false as the idea of alchemy.  Some of these things can be known over time.  Other things we probably will never be able to discover.

The Example of Columbus' Errors

Christopher Columbus for example assumed that the distance of Eurasia covered 225 degrees of the globe, leaving only about 135 degrees of the globe to cover.  He calculated the circumference of the Earth to be the equivalent of 22,500 kilometers (13,980 miles) based on what he knew (the estimated length of the Eurasian land mass) and assumed he only had to travel the equivalent of 2300 miles from the Canary Islands to Japan.

However, the size of the ocean between Europe and Asia was in fact about 8.5 times longer than Columbus had estimated (19,600 miles from the Canary Islands to Japan).  The circumference of the globe was about 40,000 km (about 25,000 miles).  So we can see here that Columbus made an error based on assuming that what he knew in relation to what he did not know.  (Columbus' critics actually recognized that with a distance of over 19,000 miles to Japan [using Ptolemy's accurate estimate], no ship of the era could reach Asia from the West without the crew starving to death).  This is an example of an error based on erroneous scientific calculations assuming they were correct.

There was a second error which was something they could not know.  The educated people of the time, even those who accepted the ideas of Ptolemy (who more accurately estimated Eurasia to be about 180 degrees of the globe, not 225 degrees)  believed that it was one massive ocean between Europe and Asia.  What they could not know was there was another landmass between Europe and Asia going west.  This is an example of an error based on assuming that what we do not know will be in keeping with what we do know.

One couldn't prove or hypothesize the existence of the Americas from the knowledge of European sciences.  The Americas existed, even though prior to 1492 there was no reason to believe they did.

Teacups Around Pluto and "I don't believe America exists…"

The people who might deny the existence of another land mass ("A-americanists" to coin a non existing phrase) would have seemed quite reasonable in 1491.  Sure there were some reports of a Viking "Vinland" which was believed to be an island like Greenland, and sure there are some dubious reports of the Chinese reaching it in 1421, but from what Science could know in 1491, anyone claiming the existence of another continent could be greeted with a 15th century equivalent of Jeffery Stingerstein's "Teacup argument," which runs as follows:

"I can no more prove that heaven does not exist than I can prove that there is not a miniature teacup orbiting the planet Pluto, but it does not make it ridiculous for me to say that there is no such teacup in orbit"

and not be seen as unreasonable… in 1491.  However, once it became clear that this landmass was not Asia, but a new continent (Vespucci first argued this in works published in 1504 and it was accepted by 1507), such an argument would be demonstrably false.

How this is Relevant

I am sure some atheists would object at this point saying that the example of Columbus is invalid… after all, America was discovered and verified, but if what the Christians say about God is true, the existence of God cannot be discovered in that way.

This would be to miss the point however.  Based on what was known in 1491, one could theoretically take an atheistic attitude directed towards the existence of another landmass and such an attitude would not be able to be rebutted.  In this hypothetical case, a person who claimed to have knowledge through revelation of this landmass could be ridiculed for his "mindless faith."

Yet the knowledge which one had in 1491 would be inadequate to make the claim that a landmass between Europe and Asia did not exist, or even that it was "most likely" that such a landmass did not exist.  Knowledge in 1507 showed this assumption was false, but even before 1492 this knowledge was false.

Recognizing the Difference Between "IF" and "IS"

Likewise the claim that what we know of science makes it "most likely" that God does not exist is equally foolish.  What we do not know, we cannot make assumptions on.  We can indeed make predictions based on the premise of "if this is true…" or "if my calculations are correct…" but these predictions have to recognize that IF is not the same as IS.  Because if what we think is correct turns out to be false, what we assume will turn out to be false.

Much of what is unknown may possibly be something which logically follows from what we do know.  However, we cannot say that there is no "unknown continent" out there which may show that what we think we know is actually false.  We can only say that, based on science alone, there are certain things which cannot be answered.  [From this admission, one can investigate whether or not one can know things outside of empirical knowledge, but that is outside of the scope of this article].

The Inevitable Objection and the Reply

Some will object here, claiming that we are applying a double standard, that if they cannot disprove the existence of God, neither can we prove it and therefore what I have written applies to Christians too.  The reason this objection is not valid is because Christians do not attempt to prove the existence of God based solely on what we know from science, but the atheist who invokes the "most likely" argument does.

The atheists I have discussed the issue of "more likely" with tend to base their argument solely on science without considering whether the claims of science even permits the assertions they make.  To claim "God does not exist" is to claim knowledge about what Science does not have and cannot prove.  To make the milder claim that it is "more likely" that God does not exist is to make the only slightly less unlikely claim that what we do not know is nothing more than an extension of what we do know.


Ultimately, the argument that God does not exist, or even that it is "more likely" that God does not exist cannot be supported by science.  If we let 'A' be that which we can know scientifically and let 'B' be things which are, and A (is less than) B, one can neither argue rationally that God does not exist nor that it is "more likely" that God does not exist based on science.  This doesn't mean science is useless.  It means we are not to invoke it for things it cannot speak on.

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