What Is Science?

The definition of science poses some problems for people. Everyone seems to have an idea of what science is, but actually articulating it proves to be difficult. Doing so, however, is necessary to understand what science really is and what science is not. Understanding science is, in turn, necessary because of its incredible power and influence in modern society. Ignorance about science simply isn't a viable option. The classical definition of science is simply the state of "knowing"—specifically theoretical knowledge as opposed the practical knowledge. In the Middle Ages the term "science" came to be used interchangeably with "arts," the word for such practical knowledge. Thus, "liberal arts" and "liberal sciences" meant basically the same thing.

Modern dictionaries are a bit more specific than that and offer a number of different ways in which the term science can be defined:

The observation, identification, description, experimental investigation, and theoretical explanation of phenomena. Methodological activity, discipline, or study. An activity that appears to require study and method.

For many purposes, these definitions can be adequate, but like so many other dictionary definitions of complex subjects, they are ultimately superficial and misleading. They only provide the barest minimum of information about the nature of science. As a consequence, the above definitions can be used to argue that even astrology or dowsing qualify as "science."

Distinguishing modern science from other endeavors requires focusing in particular on its methodology—the means by which it achieves results. Fundamentally, then, science can be characterized as a method of obtaining reliable—thought not infallible—knowledge about the universe around us. This knowledge includes both descriptions of what happens and explanations of why it happens.

The knowledge is reliable because it is continually tested and retested—much of science is heavily interdependent, which means that any test of any scientific idea entails testing other, related ideas at the same time. The knowledge is not infallible, because at no point do scientists assume that they have arrived at a final, definitive truth.

The knowledge involved is that about the universe around us, and that includes us as well. This is why science is naturalistic: it is all about natural processes and natural events. Science involves both description, which tells us what has happened, and explanation, which tells us why it happened. This latter point is an important factor because it is only through knowing why events occur that we can predict what else might occur in the future.

Science can also at times be characterized as a category or body of knowledge. When this is how the term is used, the speaker usually has in mind just the physical sciences (astronomy, geology) or biological sciences (zoology, botany). These are sometimes also called "empirical sciences," as distinguished from the "formal sciences," which encompass mathematics and formal logic.

Finally, science is often used to refer to the community of scientists and researchers who do scientific work. It is this group of people who, through practicing science, effectively define what science is and how science is done. Philosophers of science attempt to describe what an ideal pursuit of science would look like, but it is the scientists who establish what it will really be.

FROM: ABOUT.COM

What is the Scientific Method?
How Is It Used And What Does It Do?

Science is effectively defined by the method which actual scientists use in order to make discoveries and generally produce knowledge about the universe around us. It is this method which distinguishes the scientific process from other, generally less successful, attempts to produce knowledge about the world. Therefore, understanding science requires understanding how the scientific method works.

What is described here is, to be honest, an ideal—actual scientists do not always follow the description here perfectly, but the practice of science is nevertheless often close to the broad outlines of the ideal. It is important, however, to understand that neither the reality nor the ideal is some special or magical mental process unavailable to non-scientists.

The scientific method involves a combination of induction and deduction, each feeding back upon the other. The first part, known as the Method of Induction, is the process by which we take particular information from our senses and attempt to produce general statements about our world. For example, when we observe that fire consistently burns our fingers, we can conclude fire is generally too hot to touch.

The deductive aspect of the scientific method moves in just the opposite direction: it involves taking a general principle about the world and deducing what will or should happen in some particular instance. Thus, working from the principle that fire is too hot to touch, we can deduce that putting our foot in a fire will cause burns and pain.

Because the scientific method involves a feedback loop of induction and deduction, it often isn't possible to determine where any particular process has started—this is, in fact, one place where the practice and ideal diverge. Nevertheless, a common starting point is used here in these six steps:

1. Observation
Some aspect of the world is observed by us and we arrive at new knowledge. This information might be obtained through any or all of our senses, and it may come to us either through our intentional efforts or accidentally.

2. Repetition
Not much can be done with a single observation (usually); thus, more observations are necessary before proceeding further. Often these new observations are obtained deliberately as part of an effort to confirm or refute the initial observation in step #1. Our observations are often stated in the form of a question or problem, for example: In situation S, why does X always occur?

3. Induction
After arranging and considering our observations, we attempt to create some general principle which both describes what happened and, more importantly, explains why it happened. This principle should ideally be framed as broadly as possible and is generally called a hypothesis.

4. Deduction
Now that we have what we hope is a general principle which accurately describes and explains things which happen in our universe, it is time to do some tests to see if we are correct. This is accomplished by creating predictions—these are phrased as statement in the form "if principle P is true, then event E should occur or fact F should be true."

5. Testing
Once we have predictions, it is time to go out and actually see what we find by collecting more observations. We try to determine if some fact (F) is already true about the world or if some event (E) occurs or can be caused to occur.

6. Induction (again)
After we produce more observations, it is time to take another look at the general principle we formulated earlier. If our predictions were true, then our hypothesis has been made stronger. According to some, once this successful testing has been repeated multiple times, the hypothesis should be called a 'scientific theory.' We now might want to start looking at making our theory broader so that it can account for more diverse phenomena.

If, however, our predictions were not successful, then we must consider what went wrong. Possibilities include: our theory was mistaken and we need to reformulate it; our deductions from the theory were mistaken and we need reconsider our understanding of it; or finally, our experiments were flawed and we need to try again.

Notice that all three of those possibilities are, in fact, theories which might explain some observed phenomenon: the failure of our experiments to confirm our original theory! So, figuring out which of them is correct will involve going through the above process and using the scientific method all over again.

Hopefully it is clear from this description that this method is ordered and that the given order is important. If you hypothesize before observing and stating a problem then you are not really being scientific; and you obviously can't test a hypothesis unless you have a hypothesis to test. Moreover, this is an iterative process: testing frequently will provide new information even if the hypothesis fails the tests. If the testing stage fails, you may go back and refine the hypothesis, or go back to analysis to reconsider the problem, then progress forward through the stages again.

Sometimes you may go back to the observation stage from the induction stage if you discover that stating a clear solution to the problem is difficult. Thus it is possible to move backward through the process as well as forward. Moreover, the process can be hierarchical: each stage of the process may involve using the scientific method to solve sub-problems or related problems. So, while the overall process is fairly simple, there can be a great deal of detail and complexity in its operation.

If all of the above sounds too difficult to grasp, rest assured that in reality it's not. As a matter of fact, the scientific method is only a formalized description of what people do every day. It is not too far wrong to say that the scientific method, even when described technically, amounts to systematized common sense. To see how and why, consider the following example, used by Tim M. Berra in his book Evolution and the Myth of Creationism. First will be the simple description and second will be the formal description:

You walk into a room in your house and flick on the light switch, but nothing happens. You flick it a few more times to make sure it isn't working and then go get a replacement bulb. After you put it in, you find that it still doesn't work. Looking around at the other electrical appliances in the room, you don't see any of them working either, so you go down to the basement to check the fuse box.
You walk into a room in your house and flick on the light switch, but nothing happens. At this point, you have an observation: the light isn't coming on. Immediately you form a hypothesis: the connection isn't making proper contact. You predict that, if this hypothesis is true, then it may be possible that it will make a connection with further attempts, so you try the switch again several times.

Unfortunately, your experiment does not produce the results you hoped for, thus your prediction fails. Your experiment was valid and your understanding of the principle is probably valid, so you have to go all of the way back to the beginning to try a new hypothesis: the bulb is burned out. If that is true, then replacing the old bulb with a new one should produce light, so you go to fetch a new bulb.

Once again, your experiment fails; once again, your experiment and your understanding of your hypothesis were probably valid, so you need yet another theory. Looking around, you make the new observation that nothing else in the room is working, so you theorize that the power to the room must be interrupted. You also predict that, if this is true, you will find evidence of that in the fuse box, so you go down to the basement to check.

Both of the above are descriptions of the same series of events, with the latter simply being much more explicit about the background processes which we are almost always unconscious of. The scientific method is more formalized and explicit than how we proceed in our everyday lives, because first, it is important that nothing be missed accidentally, and second, it is important that others be able to replicate our steps in order to determine whether or not our results are valid.

It is also worth noting where this practice diverges from the ideal—for example, a hypothesis is formulated after a single observation rather than after several. Although multiple observations are preferable, sometimes just a single observation or even just a single idea is enough to begin the process of formulating hypotheses to test. There are no absolute requirements as to what we need before we start theorizing about what happens in our world.

FROM: ABOUT.COM

Scientific Theories
How Are They Developed?

Once you understand how the scientific method works, the next step in understanding science is understanding the nature of scientific theories. If scientific observations are the fuel which power scientific discoveries, then scientific theories are the engine. Theories are what allow scientists to organize and understand earlier observations, then predict and create future observations.

Scientific theories can be described by characteristics which they share in common and which differentiate them from unscientific theories. Informally, we can say that the criteria of scientific theories can be grouped into a few basic principles: scientific theories should be consistent, parsimonious, correctable, empirically testable/verifiable, useful, and progressive.

A key factor to keep in mind is that the term "theory" is used by scientists in a manner different from common usage. For most contexts, a theory is just a vague and fuzzy idea about how things work—in fact, one which has a low probability of being true. This is where we get the complaint that something in science is "only a theory" and hence shouldn't be given a great deal of credibility. For scientists, however, a theory is a conceptual structure which is used to explain existing facts and predict new ones.

According to Robert Root-Bernstein in his essay, "On Defining a Scientific Theory: Creationism Considered," to be considered a scientific theory by most scientists and philosophers of science, a theory must meet most, if not all, of certain logical, empirical, sociological and historical criteria. These groupings are important because most people tend to focus only on the logical and empirical criteria—it is easy to forget that science also encompasses important social and historical aspects which play a role in how theories are evaluated.

Logical Criteria

A scientific theory must be:

a simple unifying idea that postulates nothing unnecessary ("Occam's Razor")
logically consistent
logically falsifiable (i.e., cases must exist in which the theory can be imagined to be invalid)
clearly limited by explicit boundary conditions so that it is clear whether or not particular data are or are not relevant to verification or falsification

The above logical criteria are among the most cited when it comes to discussions about the nature of scientific theories and how science differs from nonscience or pseudoscience. When a theory includes unnecessary ideas or is inconsistent, it becomes difficult to see how it actually explains anything. When a theory is not falsifiable, it is impossible to tell if it is true or not, and thus it won't be possible to correct it via experimentation. Finally, when there aren't any clear boundaries, we'll never know if particular observations count for or against it.

Empirical Criteria

A scientific theory must:

be empirically testable or lead to predictions or retrodictions that are testable
actually make verified predictions and/or retrodictions
involve reproducible results
provide criteria for the interpretation of data as factual, artifactual, anomalous or irrelevant

The above criteria are not cited quite as often as the logical criteria, but they come close. A theory which cannot be tested empirically is useless for researchers. A theory which has not made any actually verified predictions might prove useful in the future when its predictions are verified, but not currently.

A theory which cannot provide retrodictions (to utilize present information or ideas to infer or explain a past event or state of affairs—e.g., to "retrodict past eclipses" as opposed to predicting future eclipses) may also be useful in the future, but not currently. If a theory's results cannot be reproduced, it is impossible to determine if those results were ever actually valid (rather than the result of error or fraud).

Finally, a scientific theory must allow us to better understand the nature of the data we have—after all, not all data are valid for a particular theory. Some data may be interpreted as factual (that is, they fall within the boundary conditions specified by the theory and verify its predictions or retrodictions); some may be artifactual (that is, the result of secondary or accidental influences lying outside the boundaries set for the validity of the theory); some are anomalous (that is, demonstrably valid within the bounds of the theory, but also at odds with predictions or retrodictions made by the theory); some are irreproducable and thus invalid; and some are irrelevant since they address the theory not at all.

Sociological Criteria

A scientific theory must:

resolve recognized problems, paradoxes, and/or anomalies irresolvable on the basis of preexisting theories
pose a new set of scientific problems upon which scientists may work
suggest a "paradigm" or problem solving model to help resolve these new problems
provide definitions of concepts or operations which will help other scientists solve problems.

The above criteria are more often recognized by critics than supporters of science. This is unfortunate because they are not actually problems—on the contrary, they underscore the fact that science is generally something ultimately done by a community of researchers and that many scientific problems are problems discovered by the work of a community.

Thus, a scientific theory must address some problem which the scientific community needs resolved. It need not be an old problem; in fact the articulation of the theory can itself be the means of informing people about the problem. However, if there is no actual problem and we are not looking at an issue which is already covered by other theories, then how can this new theory qualify as scientific? Furthermore, this new theory must offer a means of resolving the problem—simply pointing it out isn't enough.

Historical Criteria

A scientific theory must:

meet or surpass all of the criteria set by its predecessors or demonstrate that any abandoned criteria are artifactual
be able to explain all of the data gathered under previous relevant theories in terms either of fact or artifact (no anomalies allowed)
be consistent with all preexisting ancillary theories that already have established scientific validity

These historical criteria are closely related to the sociological ones. A scientific theory does not need to simply solve some problem, but it needs to do so in a way which is superior to other, competing theories which people have offered in the past. In addition, a good theory needs to be able to explain more data than the competition—scientists prefer fewer theories which explain more things rather than many theories, each of which explains very little. All of this is what ensures that scientific theories increase in their explanatory power.

Legal Criteria

Root-Bernstein does not actually list any legal criteria for scientific theories—and ideally, there wouldn't be. Science is a matter of research, not a matter of law. However, in 1981, there was a trial in Arkansas over an "equal treatment" law that made creationism a required subject which had to be taught whenever evolution was taught. This law was challenged and overturned, as were similar laws elsewhere. Ultimately the U.S. Supreme Court made the determination that such laws were unconstitutional.

The Arkansas trial is frequently highlighted because it was the first of its kind, and also because of the very comprehensive judgment that came out of it. The trial had several high profile, well known scientists involved in giving evidence, including descriptions of science, so the outcome of the trial has some relevance. In his ruling, Judge Overton found that science has four essential features:

It is guided by natural laws, and is explanatory by references to natural laws.
Science is testable against the empirical world.
Its conclusions are tentative, not the final word.
It is falsifiable.

These criteria are compatible with or repeat the more detailed criteria outlined above. So, at least in the U.S., there is a legal precedent for answering the question, "what is science?"

Summary

Overall, the criteria for scientific theories can be loosely be summarized by a few basic principles. Scientific theories are:

Consistent (internally and externally)
Parsimonious (sparing in proposed entities or explanations)
Useful (describes and explains observed phenomena)
Empirically Testable & Falsifiable
Based upon Controlled, Repeated Experiments
Correctable & Dynamic (changes are made as new data is discovered)
Progressive (achieves all that previous theories have and more)
Tentative (admits that it might not be correct rather than asserting certainty)

It is true that the exact nature of science is open for debate, and some if not all of these criteria could be questioned. However, in practice, the above criteria are a pretty good description of characteristics that one would expect a theory to posses for it to be considered a scientific theory. Lacking one or two might not mean that a theory isn't scientific, but only if there are very, very good reasons; lacking most or all, however, will certainly disqualify an idea from being genuinely scientific.

FROM: ABOUT

Scientific Laws
What Are They? How Are They Used?

If science does not claim to arrive at absolute, definitive truth, then what are scientific laws? Doesn't the existence of a law imply the existence of a truth, not to mention a lawgiver? And if science does not provide us with truth, does that mean that science does not deal with facts?

There can be a lot of confusion about the concepts of laws and facts within scientific research, and one result has been erroneous impressions not just about what these categories are, but also about how science itself works. That is why it is necessary to take some time to clear up this terminology.

The concept "law of science" is an inheritance from the earliest days of science when it was believed that the universe operated in the way it did because God established natural laws which dictated how things should act. Of course, everything but humans followed these laws, and so the movement of objects could be accurately predicted simply by coming to better understand the laws created by God. In this way, science in its infancy was very close to theology.

Over time, the premise of a "lawgiver" who established the workings of nature was abandoned in favor of a naturalistic position. The concept of "laws of science" or "natural laws," however, remained—it had become a standard means of expression which stuck like a bad habit. We can still see it today used in textbooks to refer to basic principles of how nature works.

One common means of explaining the continued use of this concept is to say that it refers to broad and general regularities in the behavior of matter and/or energy which occur over a wide ranges of space and time and which have been observed so many times that future changes are no longer given much consideration. This is plausible in theory, but problematic in practice.

If we look through, say, a physics textbook to examine how the terms "law" and "theory" are actually used, we won't find that the above criteria are the deciding factor. Instead, we simply find that "law" is used with regularities which were discovered a long time ago while "theory" is applied to regularities discovered much more recently. That's why we have "Newton's first law of motion" rather than "Newton's first theory of motion" and "Einstein's special theory of relativity" rather than "Einstein's special law of relativity."

Perhaps it would be preferable if the term "law" were abandoned entirely—it certainly aids and abets those who are under the mistaken impression that science continues to operate under the premise of a lawgiver directing the events in nature. Unfortunately, such a change is unlikely—there is simply too much momentum from tradition and history preventing it.

FROM: ABOUT

Hypothesis, Theories, and Facts
Developing Ideas and Explanations in Science

The confusion over the use of the terms hypothesis and theory can be difficult to sort out. We have popular usage, popular impression of how scientists use the terms, and how the terms actually get used in science. All three perspectives share some things in common, but none of them match completely.

Popularly, hypothesis and theory are used almost interchangeable to refer to some idea which is vague or fuzzy and which seems to have a low probability of being true. In many popular and idealistic descriptions of science, however, the two words are used to refer to the same idea, but in different stages of development.

Thus, an idea is just a "hypothesis" when it is new and relatively untested—in other words, when the probability of error and correction is still relatively high. However, once it has successfully survived repeated testing, has become more complex, is found to explain a great deal, and has made many interesting predictions, it achieves the status of "theory." This is not an unreasonable perspective to take—after all, it makes sense to try to use terminology to differentiate younger from more established ideas in science.

In reality, however, such differentiation is notoriously difficult to make. Exactly how much testing is really required to move from hypothesis to theory? How much complexity is needed to stop being a hypothesis and start being a theory? Scientists themselves aren't rigorous in their use of the terms. For example, you can readily find references to the "Steady State Theory" of the universe—it's called a theory (even though it has evidence against it and many consider it disproven) because it has logical structure, is logically consistent, is testable, etc.

Perhaps the only consistent differentiation between hypothesis and theory which scientists actually use is that an idea is a hypothesis when it is being actively tested and investigated, but a theory in other contexts. It is probably because of this that the confusion described above has developed. After all, while in the process of testing an idea (and now calling it a hypothesis), that idea is treated very specifically as a tentative explanation. It can, then, be easy to conclude that hypothesis always refers to a tentative explanation, whatever the context.

If you try to use hypothesis to refer to more tentative ideas and theory to refer to more established ideas, you aren't doing anything wrong—especially if you make that clear at the beginning. A problem only develops if you insist that others do so as well and that this is how "real" scientists use the terms.

As far as "facts" are concerned, scientists will caution you that even though they will appear to be using the term in the same way as everyone else, there are background assumptions which are crucial. When most people refer to a "fact," the are talking about something which is definitely, absolutely and unquestionably true. For scientists, a fact is something which is assumed to be true, at least for the purposes of whatever they are doing at the moment, but which might be refuted at some point.

It is this implicit fallibilism which helps differentiate science from other human endeavors. It is certainly the case that scientists will act as if something is definitely true and not give much thought to the possibility that it is wrong—but that doesn't mean that they ignore it completely. This quote from Stephen Jay Gould illustrates the issue nicely:

Moreover, 'fact' doesn't mean 'absolute certainty'; there ain't no such animal in an exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are NOT about the empirical world. ...In science 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional consent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.

The key phrase is "provisional consent"—it is accepted as true provisionally, which means only for the time being. It is accepted as true at this time and for this context because we have every reason to do so and no reason not to do so. If, however, good reasons to reconsider this position arise, then we should begin to withdraw our consent.

Note also that Gould introduces another important point: for many scientists, once a theory has been confirmed and reconfirmed over and over again, we get to the point that it will be treated as a "fact" for pretty much all contexts and purposes. Scientists may refer to Einstein's Special Theory of Relativity, but in most contexts Einstein's ideas here are treated as fact—treated as if they are simply true and accurate descriptions about the world.

FROM: ABOUT

Does the Earth circle around the Sun or does the Sun circle around the Earth?
How do we know? What proof do we have? If you can't answer this basic question, you've no
business rejecting the findings of science since you don't know enough to understand what you're rejecting.

March 30, 2006