Thought without evidence is pointless, evidence without thought is meaningless.
I wanted to write that sentence before explaining where it came from or what it means to me. I want you to remember it.
It occurred to me after reading an article a reader sent me (he didn’t seem to pleased with my response, but I was just giving my opinion as he requested). It was a philosophical argument for god’s existence, specifically the Cosmological Argument. I have very little respect for purely philosophical arguments in general, mostly because an argument can be sound and logical but absolutely wrong.
Don’t get me wrong, thought experiments can be useful, but a real experiment is better. Some very famous and correct Theories in Physics came from thought experiments and were validated later on. However, had they not been proven somehow, they would not be accepted. You simply cannot know if any hypothesis is correct without testing it, and philosophical arguments, I’d say by definition, are untested outside of the realm of thought. (String theory is having some problems with this right now, but that’s a story for another day and a qualified Physicist.)
However, the greatest data in the world is utterly worthless without clear and careful thought and analysis; an incorrect interpretation of data can utterly destroy its potential. I quite frequently see evidence interpreted incorrectly, most often with faulty conclusions drawn from weak correlations (remember, correlation does not indicate causation).
In order to understand the world, our thought must be grounded in reality, and our experiments into nature must be thought about carefully. As the wonders of the scientific age demonstrate, reason and evidence go together remarkably well, but without each other they’re both quite lame.