It is just a theory

One thing I hear repeatedly from theists is that evolution is a "just a theory". In their mind, this means it is nothing more than a guess. This is what it means in everyday usage, that it means an idea, a guess, something to consider. What many of them do not understand is that the term theory in science means something different than how it is used in everyday conversation. 

What is a scientific theory? It means that a falsifiable hypothesis has passed EVERY SINGLE test. It means that predictions by the hypothesis always, in every single case, conform to the theory. It means the hypothesis explains the facts accurately. Only those ideas which pass this test are referred to as theories by scientists. And Evolution has passed every test assigned to it. Let me repeat that. It has passed EVERY test. Does that mean we know everything about Evolution? No, not at all. But there are many accepted theories that we do not fully understand. In fact, we do not FULLY understand any theory. But what is really interesting is that Evolution actually has more evidence than any other theory.

However, no matter how times this is pointed out to them, they retort, it is a theory, not a fact. This is another idea that is misunderstood by the general public. Evolution actually is a fact. However, it is not a law. Theories never become laws. Isn't that a problem for the validity of the idea? Actually, no, There are other theories that are very well known that are completely accepted. It is also somewhat misleading. Because, although Evolution and Gravity are theories, they are also describing things that are facts.

Gravity is a fact. And gravitational theory explains this fact.
Disease is a fact. Germ theory explains this fact.
That life evolves is a fact. The theory of evolution explains this fact.

They also want to argue that theories are incomplete because they are not laws. However, theories can not become laws, because the purpose of a theory is different from a law.


A theory explains a law. The law of gravity states that there is gravity- this is clearly a fact, and is concrete. Einstein's theory of gravity (or whichever theory is currently supported) explains how gravity works. Theories can be replaced if another, better explanation is formed. New theories do not need to be radically different from their predecessors, and can simply be modifications (although if the modification is very slight, it may still be considered the same theory).


So, the next time someone tries to dismiss Evolution for being "just a theory", proudly let them know you appreciate the vote of confidence.