July 07, 2011

The logic of science-2: Determining what is true

(For previous posts in this series, see here.)

An important question in any area of knowledge is being able to identify what is true and what is false. The search for what is true and the ability to know when we have discovered truth is, after all, the Holy Grail of epistemology, because we believe that those things that are true are of lasting value while false statements are ephemeral, usually a waste of time and at worst harmful and dangerous.

Aristotle tried to make a clear distinction between those things that we feel we know for certain and are thus unchanging, and those things that are subject to change. The two categories were variously distinguished as knowledge versus opinion, reality versus appearance, or truth versus error. Aristotle made the crucial identification that true knowledge consisted of scientific knowledge, and his close association of scientific knowledge with truth has persisted through the ages. It also made the ability to distinguish between scientific knowledge and other forms of knowledge, now known as the demarcation problem, into an important question since this presumably also demarcates truth from error. (This brief summary of this history is taken from the essay The Demise of the Demarcation Problem by Larry Laudan which should be referred to for a fuller treatment.)

Aristotle said that scientific knowledge was based on foundations that were certain and thus was infallible. Since he identified scientific knowledge with true knowledge, it followed that scientific knowledge had to be unchanging because how could truth ever become false?

The second characteristic of scientific (and hence true) knowledge was that it should consist of not just ‘know-how’ but also of ‘know-why’. 'Know-how’ knowledge was considered to be the domain of craftsmen and engineers. Such people can (and do) successfully build boats, bridges, houses, and all manner of valuable and important things without needing an understanding of the underlying theoretical principles on which they work. The electrician I call to identify and fix problems in my house has plenty of know-how and does his work quickly and efficiently without having to understand, or even know about, Maxwell's laws of electrodynamics (the know-why), whereas any scientist would claim that the latter was essential for really understanding the nature of electricity.

It is for this reason that Ptolemaic and early Copernican astronomy were not considered scientific during their time even though they made highly accurate predictions of planetary motions. Their work was not based on an understanding of the laws that governed the motion of objects but on purely empirical correlations, and thus lacked 'know-why'. If, for example, a new planet were to have been discovered, existing knowledge would not have been of much help to them in predicting its motion. Hence astronomy was considered to be merely know-how and astronomers to be a species of craftsmen.

The arrival of Isaac Newton and his laws of motion provided the underlying principles that governed the motion of planets. These laws not only explained the existing extensive body of data on planetary motions, they would also be able to predict the motion of any newly discovered planet and even led to the prediction of the existence of an actual new planet (Pluto Neptune) and where it would be located. Newton's theories provided the 'know-why' that shifted astronomy into the realm of science.

It was thought that it was this know-why element that made us confident that scientific knowledge was true and based on certain foundations. After all, even if a boat builder finds that all the wood he has encountered floats in water, this does not mean that the proposition that all wood will always float is necessarily true since it is conceivable that some new wood might turn up that sinks. But the scientific principle that all objects with a lower density than water will float while those with a higher density will sink seems to be on a much firmer footing since that knowledge penetrates to the core of the phenomenon of sinking and floating and gets at its root cause. It seems to have certain foundations.

As a consequence of the appreciation that 'know-why' knowledge has greater value, science now largely deals with abstract laws, principles, causes, and logical arguments. Empirical data is still essential, of course, but mainly as a means of testing and validating those ideas. Many of these basic ideas are somewhat removed from direct empirical test and thus determining if they are true requires considerably more effort. For example, I can easily determine if the pen lying on my desk will float or sink in water by just dropping it in a bucket. But establishing the truth of a scientific proposition, say about the role that relative densities play in sinking and floating, is not that easy.

So given the primacy of scientific principles and laws in epistemology, and since the discovery of eternal truths is to be always preferred over falsehood, an elaborate structure has grown around the whole exercise of how to establish the truth and falsity of scientific propositions, often requiring the construction of expensive and specialized equipment to determine the empirical facts relating to those propositions, and extensive long-term study of esoteric subjects to relate the propositions to the data.

Next in the series: The demise of infallibility


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Great series!

However I take issue with your view that Newton's laws explained the underlying principles of planetary motion (ie, the know-why).

Those laws are just mathematical formulations of what was observed. They tell us nothing about why the planets follow those formulations (or laws).

We think the know-why is the curvature of space-time. But it took Einstein to explain that. And maybe in the future, we'll conclude that it is actually the sharing of gravitons that explains why. Or maybe we'll conclude that gravity is entropic. Or maybe something else.

But then we'll ask why does space-time curve, or why do gravitons have the properties they have, or why does gravity exist as an emergent entropic phenomena?

Religionists will attribute the root cause(s) to the creator. Atheists to the anthropic principle.

Posted by healthphysicist on July 7, 2011 09:34 AM


The way to respond to such religious arguments is to ask the believer what is the kind of ultimate scientific answer they would accept as precluding the existence of god. I predict they will not be able to do so and their request for such an final answer will be exposed as disingenuous.

By contrast, I can think of any number of events that would cause me to believe that there is a god.

Posted by Mano on July 7, 2011 10:00 AM

Actually, it was Neptune that was discovered via the errors in position of Uranus, not Pluto.

Pluto was discovered via brute force.

Posted by Dean on July 7, 2011 10:28 AM


You are, of course, right.

It is when I am writing about the things that I am most familiar with that I make silly errors because my brain goes into autopilot, always a bad thing.


Posted by Mano on July 7, 2011 10:50 AM


A "sophisticated" religionist (the role I'm trying to take on here) would say there is no scientific answer which would preclude the existence of god. Such an answer doesn't exist because god does exist, the Universe is evidence of that. As an atheist, you are looking for evidence within god's creation that god doesn't exist. Yet, you are surrounded by the evidence and don't see it!

This is because a priori, you have ASSUMED God doesn't exist, and you need other evidence besides the known Universe. The religionist ASSUMES a priori that god does exist (using the known Universe as evidence), and any other facets you propose as evidence that god doesn't exist, simply offers a new way of understanding god's creation. Aterall, we're only humans...our understanding of god's creation isn't expected to come easy.

And in the end, all you can say is the mass of an electron, for example, is what it is because that's what it is. A religionist finds that non-explanatory. It doesn't provide a "know-why".

So what I've found amongst "sophisticated" religionists is that they find your arguments are old and tired. They see you as just not getting it.

And from your point of view, they just don't get it.

Posted by healthphysicist on July 7, 2011 11:17 AM

The symmetry you suggest does not exist for the reason that I can specify what it would that would show me that my assumption is wrong.

For example, suppose god commandeers every TV and radio to say that at a specified time the next day, he will stop the world from rotating for 24 hours. If that happens, I will admit that I was wrong and that god exists.

What can a religious believer specify that would convince him/her that god exists?

Posted by Mano on July 7, 2011 11:32 AM

The "marvelous" Universe.

They percieve a choice between this marvelous Universe being created by god or by chance. They perceive "by chance" as being ridiculously improbable. Therefore, it was created. god is the entity that did the creating.

They perceive your example of the TV to be a caricature...even if a voice said that and caused the earth to stand still, it wouldn't mean that was the creator of the universe. It might be. But of course, god has no mandate to satisfy your need for a particular form of evidence. You are the one who has chosen to ASSUME god doesn't exist in the first place, though the evidence of his creation surrounds you.

In other words, you are looking for a particular sort of exotic leaf as evidence of the forest, but you're not seeing the forest.

You just don't get it!

(smile...I've really put myself in a slimey position. Of course, I'm just synthesizing what I perceive to be the core religionist argument. It's a tougher nut to crack than the simple "evidence/no evidence" argument. Which is the point I'm sincerely trying to make.)

Posted by healthphysicist on July 7, 2011 12:27 PM

Sorry to interupt the Mano vs HP debate :-)

I think (and I might be wrong) that Mano made a slight typo in his previous comment:

"What can a religious believer specify that would convince him/her that god exists?"

I think that may have been intended as"

What can a religious believer specify that would convince him/her that god DOES NOT exist?

That would be symmetry.

Mano, an atheist, can specify what would need to happen in order for him to believe god exists.

What would a believer need to see to prove to him/her that god does not exist?

Posted by henry on July 7, 2011 12:40 PM

Henry is right, I made the typo he corrected.

But, healthphysicist, it does not matter if my TV suggestion is a caricature or not. However outlandish, the point is that I CAN specify a situation where my belief that there is not god would be on the line.

Can the religious believer do the same?

Posted by Mano on July 7, 2011 01:45 PM

Professor/henri -

Yes and no....which sounds like tapdancing, but it's not. It's because I'm not speaking for myself, but only making an argument based on what I perceive others are saying.

The Professor has defined a unique circumstance which would challenge his denial of god. But there are some atheists for whom there is no possibility of evidence to convince them of god:

Similarly, there are likely some sophisticated religionists for whom there may be no situation to convince them that god doesn't exist. And there may be some who would find certain circumstances convincing that god doesn't exist.

If a voice appeared on TV and radio and said it was from the 15th dimension and explained how they had an experiment go awry many millenia ago which led to the formation of our universe...that would certainly convince me to drop god, if I was a religionist. But then, some religionists could also posit that god created the 15th dimension.

(Some atheists might even suggest that the god, that the Professor described hearing on TV/radio is more likely to be aliens playing on our human superstitions, and pretending to be god, then actually being god.)

So I see positing outlandish "circumstances" as a dead-end.

Posted by healthphysicist on July 7, 2011 02:47 PM


If you can get a religious believer to say these things, then you can walk away satisfied that you have won the debate even if they do not concede the point. Such people are atheists but just cannot bring themselves to acknowledge the fact. Give them time.

Really religious people will never concede that god is unnecessary.

Posted by Mano on July 7, 2011 09:39 PM

But they are not atheists...they acknowledge there is a knowledge vacuum. They choose to fill the vacuum with god until a better answer becomes available.

Giving them time is like coming up with a date in which one can reasonably expect aliens to communicate with us on TV and resolve the knowledge gap.

I don't see that happening in our lifetime.

Anymore than I see god coming on TV in our lifetime to convince you.

To say those people are atheists is equivalent to them saying that you are religious. You have faith in no-god, and they have faith in god.

You probably find that ridiculous and maybe even insulting. They might find your statement ridiculous and maybe even insulting.

Maybe you just need more time.

(HA!...but I hope you do see that the same type of projections work both ways (theism atheism). One's starting point is either god exists or not, and this choice isn't evidence-based in the traditional scientific reasoning sense.)

And I've come to realize that this is how religious scientists see things. The simplistic atheist response to religious scientists is that they just show that people can hold contrary thoughts.

Even though people can hold contrary thoughts, that isn't what's happening with religious scientists. As I've described it, this is why they can find faith and science compatible. Whereas an atheist scientist can't.

Posted by healthphysicist on July 8, 2011 10:41 AM


Do you think that over time there are more non believers in god/gods?

I have to believe that initially nearly all humans believed in a god of thunder or god of fire. Either one god or some polytheistic stew.

Today it is not unusual to find someone who is an atheist.

It seems that over time that gap is being filled less and less with god.

The result is what Mano has written about before. God has been painted back into a corner where all he did was create the universe and now does not interact with it in any way.

Posted by Henry on July 9, 2011 11:32 AM


I don't know because many atheists of the past were not as outspoken as those of today. However, a recent Pew poll found that more than 90% of Americans believe in god, with 70% of Americans ABSOLUTELY CERTAIN!

Since social conditions for most people are worsening (more unemployement and poverty, poorer public education, too expensive college education, etc.) I don't expect any sudden changes from those terrible numbers. Despair and lack of education breed religiosity.

"It seems that over time that gap is being filled less and less with god."

Maybe for you, because you are making the fundamental error of not realizing that you have assumed that the Universe itself is not evidence of god. You have no data upon which you can make this assumption. Then, you have likely forgotten that science is about explaining the Universe, only appealing to what we find within the Universe itself (we are restricted from explanations which appeal to a god).

And so you have likely developed a self-fulfilling prophecy leading you to accept atheism over cartoonish forms of theism (Judiasm, Christianity, Islam).

However, if we define the Big Bang as God's Creation, gravity as God's Will 1, the strong force as God's Will 2, etc., then god is abundantly active in our Universe.

Want more "evidence"? If god's will is abundantly active in our Universe then I predict that prayer will be ineffective (after all why would god respond to humans? He follows his will!)

Guess what? Prayer is ineffective! More evidence for god! (just the opposite of the traditional view)

Posted by healthphysicist on July 9, 2011 02:04 PM