Misusing scientific terms is popular within some Christian circles, but perhaps it’s simply inadvertent. Let’s clear up a few terms, starting within mathematics and logic.
- An axiom or postulate is a proposition (statement) taken as a given.
- A lemma is an intermediate proposition or stepping stone rather than the final result, which is a theorem.
- A corollary follows readily from a theorem—it’s often simply another way of stating the theorem.
Lemmas, theorems, and corollaries are all proven, but proofs are only possible within mathematics and logic, not within science.
By contrast, all scientific statements are provisional. A scientific hypothesis is a testable explanation for a phenomenon. It explains and predicts. Once a hypothesis has proven itself, it becomes a scientific theory.
A scientific law is a description of a natural phenomenon, often an equation. Laws and theories are both well-tested, widely or universally accepted within the field, and falsifiable. The key thing to remember is that a theory explains while a law describes.
For example, germ theory, quantum theory, and the theory of evolution are explanations. Boyle’s law, Ohm’s law, and Newton’s law of gravity are all descriptions (and are all equations).
To see the difference, consider Ohm’s Law, I = V/R. This is a description of how electrical current, voltage, and resistance are related. Why it works this way is not part of Ohm’s Law.
A common misconception is that scientific hypotheses mature into theories, which mature to facts or laws. Instead, facts (the observations from an experiment, for example) lead to hypotheses (a plausible but immature explanation), which lead to theories (well-evidenced explanations). In the category of scientific explanations, a theory is as good as it gets and it doesn’t graduate to become a law.
It’s a little wrong to say a tomato is a vegetable;
it’s very wrong to say it’s a suspension bridge.
— Stuart on Big Bang Theory
(This is an update of a post that originally appeared 2/27/12.)
Photo credit: Marvin (PA)