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The Role of Science

Science can be seen as the ultimate extension and development of critical thinking. Science is an institution devoted to identifying ideas of substance, treating them as maps for real-world action, testing the ideas, then modifying or updating the maps as required by the evidence.

Above all, science involves putting ideas to the test. Noted philosopher Karl Popper described the basic pattern of science as "conjection [speculation] and refutation."

Retired Stanford University mathematician George Polya put it more simply, at the age of 90. "What is the scientific method except Guess and Test?" (Blakeslee, 1978)

What idea is expressed by Popper and Polya?

The word "science," while familiar to all, does not automatically bring joy to the hearts of students. I asked two classes of over 250 students each to report anonymously whether they had ever taken a science course they truly enjoyed.

In one class, 57% said yes, 30% said somewhat, and 12% said no. In the other class, 54% said yes, 28% said somewhat, and 17% said no.

That means nearly 40% of the students (mostly first and second year students in an introductory psychology course) had less than inspiring experiences of science. The good news is that nearly 60% had positive experiences.

If you are one of the 40% whose early science courses were uninspiring, you might want to give science a fresh look in college. Science is a remarkable institution in human society.

Science is international in scope, and it is not limited by any particular religious, political, or philosophical system. It is powerful, relentless, accumulating more reliable knowledge each year.

Uniquely among belief systems (if you want to call science a belief system) science is self-correcting. It criticizes its own assumptions and previous findings.

Scientists build upon their successes, but they also continually re-check and correct yesterday's knowledge. For example, Einstein's theories, proposed in the early decades of the 1900s, are tested in new ways every year.

What is unique about science as a belief system?

The subject matter of science is unlimited. Science should not be boring! If it is, find another topic; there should be scientific studies of that, too. Whatever it is you find interesting about life, about reality, science can help you study it and learn more about it.

Model Building or "Mapping" Reality

In a book titled Scientific Literacy and the Myth of the Scientific Method (1992) Henry H. Bauer offered three metaphors for the activities of scientists.

The puzzle: scientists are largely motivated by puzzle solving. They want to explain things that are strange or unexplained. They gain satisfaction from achieving new insights into how things work.

The filter: scientists start with lots of different ideas, particularly in frontier areas with problems to be solved. Many ideas are eventually disproved. Scientists try to filter out misleading and false claims.

The map: scientific theories are like maps. They preserve information about selected portions of reality. Like maps, they are schematic (incomplete or skeletal) but extremely useful in particular situations.

What three metaphors did Bauer use to describe the activities of scientists?

The map metaphor is potentially deep. (It might not even be a metaphor; maps and theories are two of a kind.) Maps are familiar to everybody, and they can be used to draw attention to several important facts about scientific theories:

Not even the best map is complete. Our theories never capture the full complexity of any system in the universe, nor are they intended to. No model contains as much detail as the system being modeled.

Moral: You can expect a theory to be accurate but you cannot expect it to be complete .

Maps come in specialized varieties that are superior for different purposes.

If you need to know about land elevations, a topographical map excels. If you need to travel on a highway system, use a road map.

If you need to predict the weather, a weather map is best. These maps look different (even if they refer to the same territory) because they are designed to highlight different sorts of information.

Similarly, there are many different scientific theories in psychology. No one theory covers all situations.

But this does not mean all maps are equal. Some are better for specific purposes. You would not want to drive across the country using a weather map instead of a road map.

Moral: among different types of maps, some are superior for particular tasks.

All different maps should be consistent with each other, and none should contradict each other.

There should be nothing in a topograph­ical map (showing land elevations) contradicting what you see in a road map or a weather map. One implication of this was noted on the page about critical thinking: nothing you learn in physics should contradict what you learn in biology, chemistry, or psychology.

Scientific theories describe different aspects of the same reality. The maps should fit together and be mutually consistent, while emphasizing different types of information.

Moral: among different scientific theories, none should contradict any other.

When errors occur in maps, they can be corrected by gathering data. Suppose you found that two maps of the same territory did contradict each other.

This can happen because of accidental errors or because map makers deliberately insert non-existent roads into a map. That allows them to tell if another company has copied their map, violating copyright.

map with error
Maps, like theories, can have errors.

We found two such non-existent roads, shown here, in a map of our home town.

If two maps disa­gree, then one of them must be wrong. You can resolve the issue by gathering data. For example, go to the site of the mystery roads and see if they are there.

Moral: when theories contradict each other, the difference can be resolved by gathering evidence.

Even the best maps must be continually updated and corrected. Scientific theories in an area of lively research never stand still for long.

One scientist estimated that the average lifespan of a modern scientific theory in the life sciences (such as biology, genetics, or neuroscience) is about three years. After that, new findings or details make it obsolete.

A three year lifespan for a theory might sound discouraging if you just worked for years to publish a scientific paper. However, this is the sign of an active and developing science.

If you can use a 20-year-old map to navigate a city, the city must not be growing. If theories stay the same for many years, that might indicate a stagnant area of research. If theories change as the result of new evidence, that means people are still finding out new things.

Moral: Even good theories become obsolete and outdated. Scientists continually look for new and more accurate information.

How is the map metaphor instructive?

This last point relates to a unique char­acter­istic of science, one which sets it apart from all the other ideologies and belief systems in the world. It was mentioned earlier but bears repeating.

Science is self-correcting. It tries to change itself. This is very different from other belief systems.

How is science unique among systems of thought?

Science is not devoted to any particular point of view, although individual scientists might be. Science as an institution aims at accuracy, not dogma (ideas which cannot be challenged).

If new research forces a re-examination of old ideas, that is considered a plus, not a minus. In this sense, science is a self-correcting system. It has numerous ways of testing its own ideas and assumptions, modifying, deleting, or improving them as necessary.


Bauer, H. H. (1992) Scientific literacy and the myth of the scientific method. Urbana, IL: University of Illinois Press.

Blakeslee, A. (1978, May 7). At 90, he fights to make math palatable. Ann Arbor News, p. E-2.

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