A Brief Return to Testability

As a brief follow up on the claims made by Rusty Lopez concerning the "testable creation model" that is advocated by Hugh Ross and Fuz Rana of Reasons to Believe, I'd like to quote something on the subject of testability written by Doug Theobald, one of the folks who has contributed so much to the Talk.Origins Archive. A biochemist from the Univ. of Colorado at Boulder, Doug wrote one of the primary FAQs in the archive entitled 29+ Evidences for Macroevolution: The Scientific Case for Common Descent. It is at his suggestion that I am posting this, because it really does help explain why the notion of testability that is being offered by Ross and Rana (via Rusty) is entirely different than the scientific meaning of testability. Here is how Doug explains the matter in his FAQ:

Scientific theories are validated by empirical testing against physical observations. Theories are not judged simply by their logical compatibility with the available data. Independent empirical testability is the hallmark of sciencein science, an explanation must not only be compatible with the observed data, it must also be testable. By "testable" we mean that the hypothesis makes predictions about what observable evidence would be consistent and what would be incompatible with the hypothesis. Simple compatibility, in itself, is insufficient as scientific evidence, because all physical observations are consistent with an infinite number of unscientific conjectures. Furthermore, a scientific explanation must make risky predictions the predictions should be necessary if the theory is correct, and few other theories should make the same necessary predictions.

As a clear example of an untestable, unscientific, hypothesis that is perfectly consistent with empirical observations, consider solipsism. The so-called hypothesis of solipsism holds that all of reality is the product of your mind. What experiments could be performed, what observations could be made, that could demonstrate that solipsism is wrong? Even though it is logically consistent with the data, solipsism cannot be tested by independent researchers. Any and all evidence is consistent with solipsism. Solipsism is unscientific precisely because no possible evidence could stand in contradiction to its predictions.

There is also a very well written section in his FAQ concerning common misconceptions about the scientific method, especially how words like "proof" and "theory" are used in science to mean something quite different than the way the average person uses them colloquially. Well worth the time.