Science, in its broad sense, is becoming the foundation of modern civilization: medicine, industrial production, agricultural production, construction, war and many more facets of our culture are based on science and its offshoot, engineering. The major exceptions to this trend are religion and morality and other faith-based systems which are independent of science. In spite of this trend the true nature of science is misunderstood and the term, science, is sorely misapplied. There is no authoritative body, elected, appointed or otherwise, that provides a definition of science which everyone must accept. Nevertheless there is a working understanding of what science is that exists among the working scientists. I give a definition here that I believe encompasses the definitions of many active scientists. It is simple and brief but read carefully defines the essential concepts and attributes of science. The following is a definition of terms and a simple definition of science with some comments.

What Science Is:

1) Science is a self correcting system. It constantly improves itself by asking more profound questions and seeking more comprehensive answers and better explanations.

2) Sciences progresses by making measurements which validate explanations; and constructing explanations which suggest new phenomena and measurements which will validate them or not.

3) The quality of an explanation is determined by an implicit consensus of experts on its ability to most accurately explain the widest range of the most basic phenomena with a minimum of assumptions and variables.

4) Science is the collective belief of the practicing, scientific experts, not the belief of one or a few scientists. On the "cutting edge" there is often great confusion until a new explanation is fully understood and vetted; accepted or rejected as the evidence dictates; new experimental data are often required to resolve questions.

5) Science is an iterative process constantly replacing its best explanation by a better explanation as new measurements and understanding become available. Many of the old explanations are still accurate under abbreviated ranges of the parameters. Not all explanations replaced by better explanations are useless. They may be remarkably accurate over wide ranges of the data and fail only in the true extremes. They can be quite reliable in the restricted ranges and the preferred alternative in that range because of ease of application. In the early history of science some older explanations were relatively useless and in fact were not science-based.

6) Science includes applied science and engineering as an attempt to better predict the solutions to practical problems through understanding and reliable measurement.

What Science Is Not:

1) It is not a search for "absolute truth" but is a search for better explanations explaining an increasingly wider range of phenomena. Science often uses the terms "truth", "true","false", "right", "wrong", etc. but they are informal euphemisms for "better agreement" and "worse agreement". A "better absolute truth" is an oxymoron. If the old truth was absolute then there is no better one and if the new truth is better than the old one, it was not absolute. Further, if one possesses the absolute truth then a continuing endeavor for a better absolute truth is doomed to failure, is meaningless and the effort is not science.

2) It is not an authoritative, faith-based belief system but is a system in which the validity of an explanation is determined not by authority but by its agreement with all of the valid and relevant data. If science is to be considered a faith-based system then the faith is vested in the relevant and reproducible data; not in the theories and the experts who espouse them. Also, the belief that more study will eventually produce a better explanation is a faith-based belief. But the content of the science-based system is not faith-based.

3) Science is not a failure because it can not explain everything; scientific progress takes time. New measurements uncover new phenomena to be explained; there is a lot science can't explain yet. Theories are subject to continuing improvement and eventually replacement. The gaps in human knowledge and scientific explanation have been known as "Gaps of the Gods"; were frequent in early science; and have been reduced in number by science's successes. Today it is well recognized that these gaps are not a failure of science but the normal attribute of a continuing human effort to be slowly eliminated by progress.

4) Science is not determined by legislatures but in the world-wide, free and open disputations of science.

5) Mathematics is not science for mathematics exists as an axiomatic system independent of its agreement with the measurements of natural phenomena. It is a most powerful tool of science for its insights as well as its computational capabilities.

6) Science is not just the determination of "statistical correlation" as the sole evidence of "cause and effect". As Karl Gauss said, "The crowing of the cock does not cause the rising of the sun." Other evidence in addition to correlation is required to place cause and effect on a sound scientific basis.

7) Science is not anti-religious; it concerns itself with the measurable and predictable, not with the arbitrary acts of supernatural entities nor questions of "good and evil". Science may say," By the rules of science, this is a better explanation." But it does not try to supplant religious belief. Proper subject matter for the scientific methodology must meet the above defined characteristics; if an explanation does not, then science can make no statement except that it is not a proper subject for scientific inquiry.

8) NOTA BENE: This exclusion of some religious topics is based only on the arbitrary and thus unpredictable nature of the explanation and the fact it doesn't comport with the rules of science: Religious subjects which do obey the rules are a proper subject of the scientific process. As long as the initial state of the universe is unknown to science, a Deist god who creates the universe and the laws of nature and who has a policy of non-interference will be indistinguishable from scientific explanation.

Which Are Best: Laws or Theories?

In the current debates about science and its competitors, much is made about the validity of Laws and the guesses of Theory but nowhere is the fallacious nature of this argument clearer than in the comparison of Newton's Laws to Einstein's General Theory of Relativity. Both deal with the gravity and the behavior of matter under its influence.

Newton's Laws of Motion	Einstein's General Theory of Relativity
Intended to explain the motion of planets and other large objects moving at modest velocities.	Intended to explain the effects of very high velocities on observations of space and time; to improve on Newton.
Gravity is an all-pervasive force of unknown origin acting between point masses and varying with the reciprocal of the distance squared.	Gravity is a manifestation of the curvature of the space-time continuum due to the presence of mass.
The above is a superficial explanation of gravity but a valid description of its effects on the motion of objects over wide ranges of parameters but not all ranges. It is largely limited to the explanation of motions and forces.	The above is a sophisticated explanation of the causes of gravity and its effects in all ranges of parameters except the smallest masses, i.e., quantum effects. It allows for the explanation of a very wide variety of observed phenomena. It contains Newton's Laws as a subset.
Thousands of applications validate these Laws in the limited range of their parameters.	Each verification of Newton's Laws can be considered a validation of Einstein's Theory and in addition, thousands of examples of verification in many different, often new, fields of physics now exist.
Verification mostly limited to the motion of planets and other massive objects. Provided insight into the motions of objects but not into the nature of the universe.	Verification is from research as diverse as: a) motions of planets and very massive bodies, b) bending of light by the sun, c) nuclear energy, d) gravitational lensing, e), corrections to global positioning systems, f) behavior of black holes and other dense objects, g) behavior of both astronomical and laboratory phenomena, and h) other extreme phenomena. Provides a deep insight into the workings of the universe.
This Law is a very useful approximation for many computations but Newton's Laws have yielded to Einstein's Theory because the latter is a better explanation of the observed universe.	This Theory set a new and powerful paradigm for modern physics. Still, it is not valid for quantum effects and all attempts to meld the two fields have not been fully successful to date. There is still a better explanation out there.

A part of this confusion over terminology is probably the existence of two differing definitions of the word, theory:

1. a well-substantiated explanation of some aspect of the natural world;

2. a tentative explanation about the natural world;

In the broad discourses of science there are three foundational explanations and they are all called theories: a) Einstein's General Theory of Relativity, b) the Theory of Quantum Mechanics, and Darwin's Theory of Evolution. They each have copious verification; calling them Laws won't change their validity and status one bit. Their validity depends on their ability tp explain natural phenomena and data not on their names.

A second cause of confusion is the word: Uniformitarianism (A terrible word for a simple concept) which states that "the principles of nature have been uniform through time". This concept is known in the physical sciences as the Principles of Space, Time and Orientation Invariance.

The concept could be rephrased in the terms of the above science definition as: Given two similar phenomena at different times and places, the same sets of causes will produce similar results. In other words, if today's results have proven causes, then in the past the same results under similar circumstances had similar causes or, simply, "Nature, once understood, is Rational. This concept is essential to the predictability of an explanation and without predictability there is no testing and without testing there is no science. The concept is not made invalid by slow, predictable changes in fundamental constants as these results are predictable.

An additional consequence of this principle is that no experiment can be truly repeated as time (and the space coordinates) move on. Thus there are no differences between past natural phenomena and current experiments except the observation may be more complete in the latter. Repeated experiments are correctly regarded as different instances of the same phenomena under similar circumstances, no different from the multiple observations of similar events in the historic sciences. The frequent rejections of evolution for lack of duplicate experiments are simply not valid.