The definition of "Theory" and perhaps other big words...

[piece-it pete]

big at least in meaning.

Well Paul you have piqued my curiosity.

In an attempt to de-ignorize and de-stupify myself I'm starting this thread.

We've got your definition:

"Theories are designed to explain WHY facts are. In scientific epistemology, a theory is a well substantiated explanation, that is there is sufficent reason and evidence as to why we should think that a given explanation (evolution, gravity) is valid."

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Merriam-Webster:

http://www.m-w.com/cgi-bin/dictionar...heory&x=9&y=10

Main Entry: the·o·ry
Pronunciation: 'thE-&-rE, 'thi(-&)r-E
Function: noun
Inflected Form(s): plural -ries
Etymology: Late Latin theoria, from Greek theOria, from theOrein
1 : the analysis of a set of facts in their relation to one another
2 : abstract thought : SPECULATION
3 : the general or abstract principles of a body of fact, a science, or an art
4 a : a belief, policy, or procedure proposed or followed as the basis of action b : an ideal or hypothetical set of facts, principles, or circumstances -- often used in the phrase in theory
5 : a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena
6 a : a hypothesis assumed for the sake of argument or investigation b : an unproved assumption : CONJECTURE c : a body of theorems presenting a concise systematic view of a subject
synonym see HYPOTHESIS

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This useful definition came up while searching for "scientific theory":

http://aether.lbl.gov/www/classes/p10/theory.html

"A scientific theory is a synthesis of well-tested and verified hypotheses about some aspect of he world around us. When a scientific hypothesis has been confirmed repeated by experiment, it may become known as a scientific law or scientific principle. A scientific fact may be defined as an agreement by competent observers of a series of observations of the same phenomena. From time to time scientific facts are revised by additional data about the world around us. Scientists often employ a model in order to understand a particular set of phenomena. A model is a mental image of the phenomena using terms (or images) with which we are familar. For example, in the planetary model of the atom scientists visualize the atom as a nucleus with electrons orbiting around it in a manner similar to the way that planets revolve around the Sun. While this model is useul in understanding the atom, it is an over-simplified description of a real atom and does not describe/predict all of its attributes."

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Actually Paul very similar to yours, with the large IMO exception of "well tested", "verified", and "confirmed". The above professor goes on to say:

"Here are five criteria that are generally used when comparing theories and a new theory statisfying these will then replace a previously accepted theory.

I. The previously accepted theory gave an acceptable explanation of something, the new theory must give the same results.
II. New theory explains something that the PAT [Pete note: Previously Accepted Theory]either got wrong or, more commonly, did not apply.
III. Makes a prediction that is later verified.
IV. Elegance - Aesthetic quality - simple, powerful includes universal symmetries. That is simple, easy-to-remember or apply formulation, experssed as some symmetry of nature, be powerful enough to used in many applications
V. Provide a deeper insight or link to another branch of knowledge"

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While searching for the above info I came of course across many many references to "Scientific Method". Here's an online definition:

http://en.wikipedia.org/wiki/Scientific_method

The scientific method or process is considered fundamental to the scientific investigation and acquisition of new knowledge based upon physical evidence. Scientists propose new assertions about our world in the form of theories: observations, hypotheses, and deductions. Predictions from these theories are tested by experiment. If a prediction turns out to be correct, the theory survives. Any theory which is cogent enough to make predictions can then be tested reproducibly in this way. The method is commonly taken as the underlying logic of scientific practice. The scientific method is essentially an extremely cautious means of building a supportable, evidenced understanding of our world.
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Interesting how prediction is important enough to be mentioned multiple times. It reminds me of the Russian scientist in the old sci-fi novel "The Black Cloud" (Fred Hoyle, 1957), who says throughout the story "Theory nothing. Prediction everything".

So, to use your two examples, evolution and gravity, I see that one (gravity) has proof in prediction and reproductable testing and the other (evolution) has *none*.

So why on Earth or elsewhere would evolution be a litmus test of rationality, outside of prejudiced views - the enemy of scientific method?

Pete