What is science, exactly?

One of the foundations of science is the naturalistic hypothesis, which postulates that an accurate and complete description of the world can be built upon logic and natural (that is observable), as opposed to supernatural (unobservable) objects, forces and processes.


Naturalistic thought deals only with the observable and the reproducible.

It took a remarkably long time for people to distinguish the real from the imagined, to abandon magical thinking.

It is still common for people to confuse fact and fiction.

Consider the basilisk

"Open up wide!" said Aristotle to his wife, and counted her teeth through her grin.

Thus he claimed to the very end of his life that women have fewer teeth than do men.

Old Plato would surmise without looking at all, so Ari's approach was superior; but his male bias led to a very bad call - a wrong count of her oral interior.
-Scott Harrison (3/98)


The earliest forms of science arose with the philosophers of ancient Greece, between 600 to 300 BCE. Consider Aristotle, commonly thought of as the father of the modern scientific approach.

He based his ideas on direct observation of the world. Nevertheless, his prejudices could "blind" him.

He assumed that males were superior to females. In support of that claim, he stated as fact that women have fewer teeth than men.


Often racial, sexual, religious, nationality, political, or philosophical-based prejudices, often unrecognized as such by the people who harbor them, can lead to systematic distortions of apparently "objective" observations.

A classic example was the measurement of skull shape and cranial capacity, known as craniometry, as a means of predicting mental abilities and character.

Stephen J. Gould's
The mismeasure of man
discusses the unconscious manipulation of data in the cause of ideological preconceptions.
  • Is there any guarantee that naturalistic thought can produce an accurate explanation of the world around us?
  • Are there more accurate alternatives? 
  • How did Aristotle come to make such a stupid mistake about tooth number and sex in the human? 
  • Describe what you think the response would be, if Aristotle published a scientific paper on tooth number and sex in the human.

Scientific theories and laws: Here is Richard Feynman's description of how scientific laws are generated (from “Seeking New Laws” - link to Panda's Thumb). 


"In general we look for a new law by the following process.  First we guess it.  Then we compute the consequences of the guess to see what would be implied if this law that we guessed is right. 

Then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works.  If it disagrees with experiment it is wrong.  In that simple statement is the key to science. 

It does not make any difference how beautiful your guess is.  It does not make any difference how smart you are, who made the guess, or what his name is – if it disagrees with experiment it is wrong.  That is all there is to it. 

It is true that one has to check a little to make sure that it is wrong, because whoever did the experiment may have reported incorrectly, or there may have been some feature in the experiment that was not noticed, some dirt or something; or the man who computed the consequences, even though it may have been the one who made the guesses, could have made some mistakes in the analysis.  These are obvious remarks, so when I say if it disagrees with experiment it is wrong, I mean after the experiment has been checked, the calculations have been checked, and the thing has been rubbed back and forth a few times to make sure that the consequences are logical consequences from the guess, and that in fact it disagrees with a very carefully checked experiment. 

This [analysis] will give you a somewhat wrong impression of science.  It suggests that we keep on guessing possibilities and comparing them with experiment, and this is to put experiment into a rather weak position.  In fact experimenters have a certain individual character.  They like to do experiments even if nobody has guessed yet, and they very often do their experiments in a region in which people know the theorist has not made any guesses.  …

You can see, of course, that with this method we can attempt to disprove any definite theory.  If we have a definite theory, a real guess, from which we can conveniently compute consequences which can be compared with experiment, then in principle we can get rid of any theory.  There is always the possibility of proving any definite theory wrong; but notice that we can never prove it right.  Suppose that you invent a good guess, calculate the consequences, and discover every time that the consequences you have calculated agree with experiment.  The theory is then right?  No, it is simply not proved wrong.  …


One of the ways of stopping science would be only to do experiments in the region where you know the law.  But experimenters search most diligently, and with the greatest effort, in exactly those places where it seems most likely that we can prove our theories wrong.  …

Another thing I must point out is that you cannot prove a vague theory wrong

If the guess that you make is poorly expressed and rather vague, and the method that you use for figuring out the consequences is a little vague – you are not sure, and you say, ‘I think everything’s right because it’s all due to so and so, and such and such[,] do this and that more or less, and I can sort of explain how this works …’, then you see that this theory is good, because it cannot be proved wrong!  Also if the process of computing the consequences is indefinite, then with a little skill any experimental results can be made to look like the expected consequences.  …. "
  • Do we find or build scientific theories and laws?
  • How does Feynman's description of how scientific theories are made differ from non-scientific thinking?
  • What does Feynman mean by a "definite theory"?
  • Why can definite theories not be proved to be right or true?
  • Are vague ideas scientific?

An essential part of the scientific process is its social nature; to be scientific, you must be willing to present your methods, observations, models, and predictions to the public.

This presentation is through published, peer-reviewed articles.

Once an experiment or series of observations is described and published, anyone with the inclination and the resources is free to test anyone else's model, to repeat their observations, to point out mistakes or misinterpretations, make new observations, and present new or modified models. 

These critical comments are judged by the same criteria as the original work; are they logical, and do they lead to more accurate insights or predictions about the workings of the world?

Through this process ideas are tested and unconscious assumptions are revealed.  Data may be verified or discarded, sometimes because it is wrong, more often because it is irrelevant, misinterpreted, or because of factors unknown when the data was originally collected. 

The strength of the scientific approach is its self-correcting nature.  Mistaken observations, interpretations, and hypotheses are eventually identified and discarded.

In the end, it is only how well an idea predicts real world behaviors that matters.

The scientific process produces a clear directionality – certain ideas have been dealt with, either demonstrated to be valid and useful, or mistaken or irrelevant, and discarded. 

Through science, our ability to explain the world progresses; more and more phenomena become explicable and predictions become increasingly accurate and comprehensive.

Nevertheless, we are always left with uncertainty.  Whether science produces a true description of the world depends to a great extent upon what you mean by "true".   That science can, over time, produce an accurate description of particular features of the world is well established. 

Read the talk by the author Michael Critchton: web page | pdf
We will consider questions on politics, consensus and science in class. 

  • Why is the Drake equation non-scientific? 
  • Why does Critchton link the acceptance of the Drake equation to non-scientific hysteria about global warming?
  • There are fads in science, that is times when an area of science where scientists act unscientifically - what factors lead to such scientific fads?  
  • Is there a directionality in non-scientific thought?
  • Can an inaccurate theory replace an accurate one? 
  • What is the difference between truth and accuracy?
  • What if the naturalistic assumption upon which science is based is wrong, but nevertheless produces an accurate model of the world - would you abandon science? 
  • What, in general, happens when people attempt to revise a religious idea?
  • Is the scientific approach useful in day to day life?
  • Is science democratic or elitist? 

Use Wikipedia | revised 18 November 2010