May 24, 2005

What is science?

Because of my interest in the history and philosophy of science I am sometimes called upon to answer the question "what is science?" Most people think that the answer should be fairly straightforward. This is because science is such an integral part of our lives that everyone feels that they intuitively know what it is and think that the problem of defining science is purely one of finding the right combination of words that captures their intuitive sense.

But as I said in my previous posting, strictly defining things means having demarcation criteria, which involves developing a set of necessary and sufficient conditions, and this is extremely hard to do even for seemingly simple things like (say) defining what a dog is. So I should not be surprising that it may be harder to do for an abstract idea like science.

But just as a small child is able, based on its experience with pets, to distinguish between a dog and a cat without any need for formal demarcation criteria, so can scientists intuitively sense what is science and what is not science, based on the practice of their profession, without any need for a formal definition. So scientists do not, in the normal course of their work, pay much attention to whether they have a formal definition of science or not. If forced to define science (say for the purpose of writing textbooks) they tend to make up some kind of definition that sort of fits with their experience, but such ad-hoc formulations lack the kind of formal rigor that is strictly required of a philosophically sound demarcation criterion.

The absence of an agreed-upon formal definition of science has not hindered science from progressing rapidly and efficiently. Science marches on, blithely unconcerned about its lack of self-definition. People start worrying about definitions of science mainly in the context of political battles, such as those involving so-called intelligent design (or ID), because advocates of ID have been using this lack of a formal definition to try to define science in such a way that their pet idea be included as science, and thus taught in schools as part of the science curriculum and as an alternative to evolution.

Having a clear-cut demarcation criterion that defines science and is accepted by all would settle this question once and for all. But finding this demarcation criterion for science has proven to be remarkably difficult.

To set about trying to find such criteria, we do what we usually do in all such cases, we look at all the knowledge that is commonly accepted as science by everyone, and see if we can see similarities among these areas. For example, I think everyone would agree that the subjects that come under the headings of astronomy, geology, physics, chemistry, and biology, and which are studied by university departments in reputable universities, all come under the heading of science. So any definition of science that excluded any of these areas would be clearly inadequate, just as any definition of 'dog' that excluded a commonly accepted breed would be dismissed as inadequate.

This is the kind of thing we do when trying to define other things, like art (say). Any definition of art that excluded (say) paintings hanging in reputable museums would be considered an inadequate definition.

When we look back at the history of the topics studied by people in those named disciplines and which are commonly accepted as science, two characteristics stand out. The first thing that we realize is that for a theory to be considered scientific it does not have to be true. Newtonian physics is commonly accepted to be scientific, although it is not considered to be universally true anymore. The phlogiston theory of combustion is considered to be scientific though it has long since been overthrown by the oxygen theory. And so on. In fact, since all knowledge is considered to be fallible and liable to change, truth is, in some sense, irrelevant to the question of whether something is scientific or not, because absolute truth cannot be established.

(A caveat: Not all scientists will agree with me on this last point. Some scientists feel that once a theory is shown to be incorrect, it ceases to be part of science, although it remains a part of science history. Some physicists also feel that many of the current theories of (say) sub-atomic particles are unlikely to be ever overthrown and are thus true in some absolute sense. I am not convinced of this. The history of science teaches us that even theories that were considered rock-solid and lasted millennia (such as the geocentric universe) eventually were overthrown.)

But there is a clear pattern that emerges about scientific theories. All the theories that are considered to be science are (1) naturalistic and (2) predictive.

By naturalistic I mean methodological naturalism and not philosophical naturalism. The latter, I argued in an earlier posting where these terms were defined, is irrelevant to science.

By predictive, I mean that all theories that are considered part of science have the quality of having some explicit mechanism or structure that enable the users of these theories to make predictions, of saying what one should see if one did some experiment or looked in some place under certain conditions.

Note that these two conditions are just necessary conditions and by themselves are not sufficient. (See the previous posting for what those conditions mean.) As such they can only classify things into "may be science" (if something meets both conditions) or "not science" (if something does not meet either one of the conditions.) As such, these two conditions together do not make up a satisfactory demarcation criterion. For example, the theory that if a football quarterback throws a lot of interceptions his team is likely to lose, meets both naturalistic and predictive conditions, but it is not considered part of science.

But even though we do not have a rigorous demarcation criterion for science, the existence of just necessary conditions still has interesting implications, which we shall explore in later postings.


Which way is East Antarctica?

An item in a recent issue of the journal Nature stated the there is a thickening of the ice layer in East Antarctica, as contrasted with what is happening in West Antarctica.

What puzzled me is how they could define an East and West Antarctica at all. Surely the entire coastline of Antarctica has to be North Antarctica?


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My definition of science, at least as a philosophy, is "question everything". What do you think about this oversimplified definition?

Posted by Aaron Shaffer on May 24, 2005 07:55 AM

I think a sports statistician might claim that a theory on sports teams performance might be science. So the question is, not considered science by whom?

Posted by Jim Eastman on May 24, 2005 09:46 AM

Prof. Singham --

My guess regarding Antarctica is that they've divided the continent into its parts in the Western and Eastern Hemispheres.

I'm assuming, here, that Antarctica HAS parts in both hemispheres, and is not in fact located on Mars -- geography is not exactly my strong suit.

Posted by Mark on May 24, 2005 12:12 PM


The problem is that although there are north and south hemispheres (defined by the existence of north and south poles, which in turn is defined by the axis of rotation of tthe Earth), there are no east and west "poles", so there are no hemispheres defined for East and West.

On any other continent, you can head east (or west) and you will eventually reach the sea, which defines the east (or west) coast. But Antarctica straddles the south pole and you can head due east or west and just go round in circles.

Posted by Mano Singham on May 24, 2005 01:50 PM


I think "question everything" is an important element of scientific attitude and practice, but by itself is too broad to define science. One can be scientific in the way you describe in one's approach to something (say the study of history) without that something being part of science.

The idea of identifying science with the methods science uses in acquiring knowledge has been tried and found wanting because it is very hard to pin scientists' practices to any identifiable and distinguishing methodolgy.

Posted by Mano Singham on May 24, 2005 01:55 PM


Your point is well taken. Maybe I should have been more clear and said that the kind of football theory I mentioned meets the eligibility criteria but is unlikely to be accepted as science by the scientific community. For example, a person whose interests lie in that area would find it hard to get a job in a science department or get that theory published in scientific journals.

If we allow any theory that has statistical correlations to be considered part of science, then we would have broadened the definition of science to include things well beyond anything that we now currently think of as science.

Therein lies the problem. How do we decide when something goes beyond meeting just the eligibility criteria and becomes sufficient to be considered part of science?

Posted by Mano Singham on May 24, 2005 02:01 PM

Regarding east and west, I had thought that where nature failed, politics came to the rescue, splitting the world in two at the Greenwich meridian and the International Date Line. Have I been misled? :)

Clearly, lines on a map are not as satisfying as an axis, in any case...

Posted by Erin on May 24, 2005 04:46 PM

Erin --

That was roughly my understanding of the resolution to the point that Prof. Singham raises -- I had assumed that there was some arbitrary but clear division of Eastern and Western "Hemispheres," which are obviously socially rather than geographically defined, at two meridians. However, Wikipedia at least makes it look like the demarcation is much more fluid than I imagined, though apparently there is some support for placing divisions at the lines you mention.

Posted by Mark on May 24, 2005 05:43 PM

With all this talk of "Hemispheres" I had to break out one of my favorite Rush albums. It appears that the division between East and West Antarctica is about as clear as the division between heart and mind or science and non-science. The one thing that is clear is that it is best to have both hemispheres together.

Posted by Joe Felix on May 24, 2005 07:27 PM

It had never occurrred to me until Erin raised the issue that there could be a reason for thinking in terms of eastern and western hemispheres, though both Erin and Mark make a reasonabe case. I am wondering if this is because of cultural reasons.

After all, I grew up in a different "hemisphere" and my concept of what is west and east would be different. We always used those terms in cultural contexts, as in "western culture" or "western civilization." They came to be synonymous with Anglo-European based ideas, not in terms of position based on longitudinal lines.

But I can see how growing up in the US one might be able to think that this may also be geographic. In fact, if you follow the link to the Nature article and click on the link to the map, you will see that East and West Antarctica are defined exactly the way that Erin and Mark thought it was.


Posted by Mano Singham on May 25, 2005 08:16 AM

This is a constant debate in the "library and information science" world. While library researchers create a large body of research and literature in various areas (user's need for information, usability of information, predictability of users, etc.), it is largely debated, even with the field of librarianship, if it qualifies as "science" or just application of.

Posted by Brian Gray on May 25, 2005 09:29 AM